Migrate init stage to plugins (#10689)

This commit updates the preset pass manager construction to only use plugins for the init stage. To accomplish this the previously hard coded built-in pass manager used for each optimization level are refactored to be in a plugin named "default". One thing that is changed in this PR is that the use of `generate_control_flow_options_check()` is moved to the `pre_init` stage. The reason for this is because the way the init stage was being constructed in the preset pass managers was to do initial checking of any methods, and this was unconditionally being run. This is a more logical fit for pre_init stage because it should run before any specified plugin. Fixes: #10687 Fixes: #8661
Qiskit · Aug 22, 2023 · 4a8c0ca · 4a8c0ca
1 parent e7808e7
commit 4a8c0ca
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diff --git a/qiskit/transpiler/preset_passmanagers/builtin_plugins.py b/qiskit/transpiler/preset_passmanagers/builtin_plugins.py
@@ -27,6 +27,9 @@
 from qiskit.transpiler.passes import NoiseAdaptiveLayout
 from qiskit.transpiler.passes import CheckMap
 from qiskit.transpiler.passes import BarrierBeforeFinalMeasurements
+from qiskit.transpiler.passes import RemoveResetInZeroState
+from qiskit.transpiler.passes import OptimizeSwapBeforeMeasure
+from qiskit.transpiler.passes import RemoveDiagonalGatesBeforeMeasure
 from qiskit.transpiler.preset_passmanagers import common
 from qiskit.transpiler.preset_passmanagers.plugin import (
     PassManagerStagePlugin,
@@ -47,6 +50,45 @@
 from qiskit.transpiler.passes.layout.vf2_layout import VF2LayoutStopReason
 
 
+class DefaultInitPassManager(PassManagerStagePlugin):
+    """Plugin class for default init stage."""
+
+    def pass_manager(self, pass_manager_config, optimization_level=None) -> PassManager:
+        if optimization_level in {1, 2, 0}:
+            init = None
+            if (
+                pass_manager_config.initial_layout
+                or pass_manager_config.coupling_map
+                or (
+                    pass_manager_config.target is not None
+                    and pass_manager_config.target.build_coupling_map() is not None
+                )
+            ):
+                init = common.generate_unroll_3q(
+                    pass_manager_config.target,
+                    pass_manager_config.basis_gates,
+                    pass_manager_config.approximation_degree,
+                    pass_manager_config.unitary_synthesis_method,
+                    pass_manager_config.unitary_synthesis_plugin_config,
+                    pass_manager_config.hls_config,
+                )
+        elif optimization_level == 3:
+            init = common.generate_unroll_3q(
+                pass_manager_config.target,
+                pass_manager_config.basis_gates,
+                pass_manager_config.approximation_degree,
+                pass_manager_config.unitary_synthesis_method,
+                pass_manager_config.unitary_synthesis_plugin_config,
+                pass_manager_config.hls_config,
+            )
+            init.append(RemoveResetInZeroState())
+            init.append(OptimizeSwapBeforeMeasure())
+            init.append(RemoveDiagonalGatesBeforeMeasure())
+        else:
+            return TranspilerError(f"Invalid optimization level {optimization_level}")
+        return init
+
+
 class BasisTranslatorPassManager(PassManagerStagePlugin):
     """Plugin class for translation stage with :class:`~.BasisTranslator`"""
 

diff --git a/qiskit/transpiler/preset_passmanagers/level0.py b/qiskit/transpiler/preset_passmanagers/level0.py
@@ -46,34 +46,21 @@ def level_0_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassMa
     basis_gates = pass_manager_config.basis_gates
     coupling_map = pass_manager_config.coupling_map
     initial_layout = pass_manager_config.initial_layout
-    init_method = pass_manager_config.init_method
+    init_method = pass_manager_config.init_method or "default"
     layout_method = pass_manager_config.layout_method or "default"
     routing_method = pass_manager_config.routing_method or "stochastic"
     translation_method = pass_manager_config.translation_method or "translator"
     optimization_method = pass_manager_config.optimization_method or "default"
     scheduling_method = pass_manager_config.scheduling_method or "default"
-    approximation_degree = pass_manager_config.approximation_degree
-    unitary_synthesis_method = pass_manager_config.unitary_synthesis_method
-    unitary_synthesis_plugin_config = pass_manager_config.unitary_synthesis_plugin_config
     target = pass_manager_config.target
-    hls_config = pass_manager_config.hls_config
 
     # Choose routing pass
     routing_pm = plugin_manager.get_passmanager_stage(
         "routing", routing_method, pass_manager_config, optimization_level=0
     )
 
-    unroll_3q = None
     # Build pass manager
     if coupling_map or initial_layout:
-        unroll_3q = common.generate_unroll_3q(
-            target,
-            basis_gates,
-            approximation_degree,
-            unitary_synthesis_method,
-            unitary_synthesis_plugin_config,
-            hls_config,
-        )
         layout = plugin_manager.get_passmanager_stage(
             "layout", layout_method, pass_manager_config, optimization_level=0
         )
@@ -98,7 +85,7 @@ def level_0_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassMa
         "scheduling", scheduling_method, pass_manager_config, optimization_level=0
     )
 
-    init = common.generate_control_flow_options_check(
+    pre_init = common.generate_control_flow_options_check(
         layout_method=layout_method,
         routing_method=routing_method,
         translation_method=translation_method,
@@ -107,17 +94,15 @@ def level_0_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassMa
         basis_gates=basis_gates,
         target=target,
     )
-    if init_method is not None:
-        init += plugin_manager.get_passmanager_stage(
-            "init", init_method, pass_manager_config, optimization_level=0
-        )
-    elif unroll_3q is not None:
-        init += unroll_3q
+    init = plugin_manager.get_passmanager_stage(
+        "init", init_method, pass_manager_config, optimization_level=0
+    )
     optimization = plugin_manager.get_passmanager_stage(
         "optimization", optimization_method, pass_manager_config, optimization_level=0
     )
 
     return StagedPassManager(
+        pre_init=pre_init,
         init=init,
         layout=layout,
         routing=routing,

diff --git a/qiskit/transpiler/preset_passmanagers/level1.py b/qiskit/transpiler/preset_passmanagers/level1.py
@@ -48,36 +48,23 @@ def level_1_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassMa
     basis_gates = pass_manager_config.basis_gates
     coupling_map = pass_manager_config.coupling_map
     initial_layout = pass_manager_config.initial_layout
-    init_method = pass_manager_config.init_method
+    init_method = pass_manager_config.init_method or "default"
     # Unlike other presets, the layout and routing defaults aren't set here because they change
     # based on whether the input circuit has control flow.
     layout_method = pass_manager_config.layout_method or "default"
     routing_method = pass_manager_config.routing_method or "sabre"
     translation_method = pass_manager_config.translation_method or "translator"
     optimization_method = pass_manager_config.optimization_method or "default"
     scheduling_method = pass_manager_config.scheduling_method or "default"
-    approximation_degree = pass_manager_config.approximation_degree
-    unitary_synthesis_method = pass_manager_config.unitary_synthesis_method
-    unitary_synthesis_plugin_config = pass_manager_config.unitary_synthesis_plugin_config
     target = pass_manager_config.target
-    hls_config = pass_manager_config.hls_config
 
     # Choose routing pass
     routing_pm = plugin_manager.get_passmanager_stage(
         "routing", routing_method, pass_manager_config, optimization_level=1
     )
 
-    unroll_3q = None
     # Build full pass manager
     if coupling_map or initial_layout:
-        unroll_3q = common.generate_unroll_3q(
-            target,
-            basis_gates,
-            approximation_degree,
-            unitary_synthesis_method,
-            unitary_synthesis_plugin_config,
-            hls_config,
-        )
         layout = plugin_manager.get_passmanager_stage(
             "layout", layout_method, pass_manager_config, optimization_level=1
         )
@@ -108,7 +95,7 @@ def level_1_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassMa
         "scheduling", scheduling_method, pass_manager_config, optimization_level=1
     )
 
-    init = common.generate_control_flow_options_check(
+    pre_init = common.generate_control_flow_options_check(
         layout_method=layout_method,
         routing_method=routing_method,
         translation_method=translation_method,
@@ -117,14 +104,12 @@ def level_1_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassMa
         basis_gates=basis_gates,
         target=target,
     )
-    if init_method is not None:
-        init += plugin_manager.get_passmanager_stage(
-            "init", init_method, pass_manager_config, optimization_level=1
-        )
-    elif unroll_3q is not None:
-        init += unroll_3q
+    init = plugin_manager.get_passmanager_stage(
+        "init", init_method, pass_manager_config, optimization_level=1
+    )
 
     return StagedPassManager(
+        pre_init=pre_init,
         init=init,
         layout=layout,
         routing=routing,

diff --git a/qiskit/transpiler/preset_passmanagers/level2.py b/qiskit/transpiler/preset_passmanagers/level2.py
@@ -51,34 +51,21 @@ def level_2_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassMa
     basis_gates = pass_manager_config.basis_gates
     coupling_map = pass_manager_config.coupling_map
     initial_layout = pass_manager_config.initial_layout
-    init_method = pass_manager_config.init_method
+    init_method = pass_manager_config.init_method or "default"
     layout_method = pass_manager_config.layout_method or "default"
     routing_method = pass_manager_config.routing_method or "sabre"
     translation_method = pass_manager_config.translation_method or "translator"
     optimization_method = pass_manager_config.optimization_method or "default"
     scheduling_method = pass_manager_config.scheduling_method or "default"
-    approximation_degree = pass_manager_config.approximation_degree
-    unitary_synthesis_method = pass_manager_config.unitary_synthesis_method
-    unitary_synthesis_plugin_config = pass_manager_config.unitary_synthesis_plugin_config
     target = pass_manager_config.target
-    hls_config = pass_manager_config.hls_config
 
     # Choose routing pass
     routing_pm = plugin_manager.get_passmanager_stage(
         "routing", routing_method, pass_manager_config, optimization_level=2
     )
 
-    unroll_3q = None
     # Build pass manager
     if coupling_map or initial_layout:
-        unroll_3q = common.generate_unroll_3q(
-            target,
-            basis_gates,
-            approximation_degree,
-            unitary_synthesis_method,
-            unitary_synthesis_plugin_config,
-            hls_config,
-        )
         layout = plugin_manager.get_passmanager_stage(
             "layout", layout_method, pass_manager_config, optimization_level=2
         )
@@ -105,7 +92,7 @@ def level_2_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassMa
         "scheduling", scheduling_method, pass_manager_config, optimization_level=2
     )
 
-    init = common.generate_control_flow_options_check(
+    pre_init = common.generate_control_flow_options_check(
         layout_method=layout_method,
         routing_method=routing_method,
         translation_method=translation_method,
@@ -114,14 +101,12 @@ def level_2_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassMa
         basis_gates=basis_gates,
         target=target,
     )
-    if init_method is not None:
-        init += plugin_manager.get_passmanager_stage(
-            "init", init_method, pass_manager_config, optimization_level=2
-        )
-    elif unroll_3q is not None:
-        init += unroll_3q
+    init = plugin_manager.get_passmanager_stage(
+        "init", init_method, pass_manager_config, optimization_level=2
+    )
 
     return StagedPassManager(
+        pre_init=pre_init,
         init=init,
         layout=layout,
         routing=routing,

diff --git a/qiskit/transpiler/preset_passmanagers/level3.py b/qiskit/transpiler/preset_passmanagers/level3.py
@@ -18,9 +18,6 @@
 from __future__ import annotations
 from qiskit.transpiler.passmanager_config import PassManagerConfig
 from qiskit.transpiler.passmanager import StagedPassManager
-from qiskit.transpiler.passes import RemoveResetInZeroState
-from qiskit.transpiler.passes import OptimizeSwapBeforeMeasure
-from qiskit.transpiler.passes import RemoveDiagonalGatesBeforeMeasure
 from qiskit.transpiler.preset_passmanagers import common
 from qiskit.transpiler.preset_passmanagers.plugin import (
     PassManagerStagePluginManager,
@@ -54,26 +51,22 @@ def level_3_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassMa
     basis_gates = pass_manager_config.basis_gates
     coupling_map = pass_manager_config.coupling_map
     initial_layout = pass_manager_config.initial_layout
-    init_method = pass_manager_config.init_method
+    init_method = pass_manager_config.init_method or "default"
     layout_method = pass_manager_config.layout_method or "default"
     routing_method = pass_manager_config.routing_method or "sabre"
     translation_method = pass_manager_config.translation_method or "translator"
     scheduling_method = pass_manager_config.scheduling_method
     optimization_method = pass_manager_config.optimization_method or "default"
     scheduling_method = pass_manager_config.scheduling_method or "default"
-    approximation_degree = pass_manager_config.approximation_degree
-    unitary_synthesis_method = pass_manager_config.unitary_synthesis_method
-    unitary_synthesis_plugin_config = pass_manager_config.unitary_synthesis_plugin_config
     target = pass_manager_config.target
-    hls_config = pass_manager_config.hls_config
 
     # Choose routing pass
     routing_pm = plugin_manager.get_passmanager_stage(
         "routing", routing_method, pass_manager_config, optimization_level=3
     )
 
     # Build pass manager
-    init = common.generate_control_flow_options_check(
+    pre_init = common.generate_control_flow_options_check(
         layout_method=layout_method,
         routing_method=routing_method,
         translation_method=translation_method,
@@ -82,22 +75,9 @@ def level_3_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassMa
         basis_gates=basis_gates,
         target=target,
     )
-    if init_method is not None:
-        init += plugin_manager.get_passmanager_stage(
-            "init", init_method, pass_manager_config, optimization_level=2
-        )
-    else:
-        init += common.generate_unroll_3q(
-            target,
-            basis_gates,
-            approximation_degree,
-            unitary_synthesis_method,
-            unitary_synthesis_plugin_config,
-            hls_config,
-        )
-    init.append(RemoveResetInZeroState())
-    init.append(OptimizeSwapBeforeMeasure())
-    init.append(RemoveDiagonalGatesBeforeMeasure())
+    init = plugin_manager.get_passmanager_stage(
+        "init", init_method, pass_manager_config, optimization_level=3
+    )
     if coupling_map or initial_layout:
         layout = plugin_manager.get_passmanager_stage(
             "layout", layout_method, pass_manager_config, optimization_level=3
@@ -118,11 +98,6 @@ def level_3_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassMa
         target is not None and target.get_non_global_operation_names(strict_direction=True)
     ):
         pre_optimization = common.generate_pre_op_passmanager(target, coupling_map, True)
-        _direction = [
-            pass_
-            for x in common.generate_pre_op_passmanager(target, coupling_map).passes()
-            for pass_ in x["passes"]
-        ]
     else:
         pre_optimization = common.generate_pre_op_passmanager(remove_reset_in_zero=True)
 
@@ -131,6 +106,7 @@ def level_3_pass_manager(pass_manager_config: PassManagerConfig) -> StagedPassMa
     )
 
     return StagedPassManager(
+        pre_init=pre_init,
         init=init,
         layout=layout,
         routing=routing,

diff --git a/qiskit/transpiler/preset_passmanagers/plugin.py b/qiskit/transpiler/preset_passmanagers/plugin.py
@@ -47,7 +47,7 @@
      - Description and expectations
    * - ``init``
      - ``qiskit.transpiler.init``
-     - No reserved names
+     - ``default``
      - This stage runs first and is typically used for any initial logical optimization. Because most
        layout and routing algorithms are only designed to work with 1 and 2 qubit gates, this stage
        is also used to translate any gates that operate on more than 2 qubits into gates that only

diff --git a/releasenotes/notes/default-reserved-plugin-name-3825c2000a579e38.yaml b/releasenotes/notes/default-reserved-plugin-name-3825c2000a579e38.yaml
@@ -2,7 +2,7 @@
 upgrade:
   - |
     The plugin name ``default`` is reserved for the :ref:`stage_table`
-    ``layout``, ``optimization``, and ``scheduling``. These stages previously
+    ``init``, ``layout``, ``optimization``, and ``scheduling``. These stages previously
     did not reserve this plugin name, but the ``default`` name is now used to
     represent Qiskit's built-in default method for these stages. If you were
     using these names for plugins on these stages these will conflict with

diff --git a/setup.py b/setup.py
@@ -134,6 +134,9 @@
             "permutation.basic = qiskit.transpiler.passes.synthesis.high_level_synthesis:BasicSynthesisPermutation",
             "permutation.acg = qiskit.transpiler.passes.synthesis.high_level_synthesis:ACGSynthesisPermutation",
         ],
+        "qiskit.transpiler.init": [
+            "default = qiskit.transpiler.preset_passmanagers.builtin_plugins:DefaultInitPassManager",
+        ],
         "qiskit.transpiler.translation": [
             "translator = qiskit.transpiler.preset_passmanagers.builtin_plugins:BasisTranslatorPassManager",
             "unroller = qiskit.transpiler.preset_passmanagers.builtin_plugins:UnrollerPassManager",

diff --git a/test/python/transpiler/test_preset_passmanagers.py b/test/python/transpiler/test_preset_passmanagers.py
@@ -70,6 +70,8 @@ def mock_get_passmanager_stage(
             ]
         )
         return pm
+    elif stage_name == "init":
+        return PassManager([])
     elif stage_name == "routing":
         return PassManager([])
     elif stage_name == "optimization":