1.1.1

bqskit/compiler/compile.py

@@ -989,37 +989,49 @@ def build_multi_qudit_retarget_workflow(
     """
     Build standard workflow for circuit multi-qudit gate set retargeting.
 
-    This workflow assumes that SetModelPass will be run earlier in the full
-    workflow and doesn't add it in here.
+    Notes:
+        - This workflow assumes that SetModelPass will be run earlier in the
+          full workflow and doesn't add it in here.
+
+        - For the most part, circuit connectivity isn't a concern during
+          retargeting. However, if the circuit contains many-qudit (>= 3)
+          gates, then the workflow will not preserve connectivity during
+          the decomposition of those gates. If your input contains many-qudit
+          gates, consider following this with a mapping workflow.
     """
+
+    core_retarget_workflow = [
+        FillSingleQuditGatesPass(),
+        IfThenElsePass(
+            NotPredicate(MultiPhysicalPredicate()),
+            IfThenElsePass(
+                ManyQuditGatesPredicate(),
+                [
+                    ExtractModelConnectivityPass(),
+                    build_standard_search_synthesis_workflow(
+                        optimization_level,
+                        synthesis_epsilon,
+                    ),
+                    RestoreModelConnevtivityPass(),
+                ],
+                AutoRebase2QuditGatePass(3, 5),
+            ),
+            ScanningGateRemovalPass(
+                success_threshold=synthesis_epsilon,
+                collection_filter=_mq_gate_collection_filter,
+                instantiate_options=get_instantiate_options(optimization_level),
+            ),
+        ),
+    ]
+
     return Workflow(
         [
             IfThenElsePass(
                 NotPredicate(WidthPredicate(2)),
                 [
                     LogPass('Retargeting multi-qudit gates.'),
                     build_partitioning_workflow(
-                        [
-                            FillSingleQuditGatesPass(),
-                            IfThenElsePass(
-                                NotPredicate(MultiPhysicalPredicate()),
-                                IfThenElsePass(
-                                    ManyQuditGatesPredicate(),
-                                    build_standard_search_synthesis_workflow(
-                                        optimization_level,
-                                        synthesis_epsilon,
-                                    ),
-                                    AutoRebase2QuditGatePass(3, 5),
-                                ),
-                                ScanningGateRemovalPass(
-                                    success_threshold=synthesis_epsilon,
-                                    collection_filter=_mq_gate_collection_filter,  # noqa: E501
-                                    instantiate_options=get_instantiate_options(
-                                        optimization_level,
-                                    ),
-                                ),
-                            ),
-                        ],
+                        core_retarget_workflow,
                         max_synthesis_size,
                         None if error_threshold is None else error_sim_size,
                     ),
@@ -1221,6 +1233,7 @@ def build_seqpam_mapping_optimization_workflow(
         IfThenElsePass(
             NotPredicate(WidthPredicate(2)),
             [
+                LogPass('Caching permutation-aware synthesis results.'),
                 ExtractModelConnectivityPass(),
                 QuickPartitioner(block_size),
                 ForEachBlockPass(
@@ -1240,11 +1253,13 @@ def build_seqpam_mapping_optimization_workflow(
                         ),
                     ),
                 ),
+                LogPass('Preoptimizing with permutation-aware mapping.'),
                 PAMRoutingPass(),
                 post_pam_seq,
                 UnfoldPass(),
                 RestoreModelConnevtivityPass(),
 
+                LogPass('Recaching permutation-aware synthesis results.'),
                 SubtopologySelectionPass(block_size),
                 QuickPartitioner(block_size),
                 ForEachBlockPass(
@@ -1264,6 +1279,7 @@ def build_seqpam_mapping_optimization_workflow(
                         ),
                     ),
                 ),
+                LogPass('Performing permutation-aware mapping.'),
                 ApplyPlacement(),
                 PAMLayoutPass(num_layout_passes),
                 PAMRoutingPass(0.1),

bqskit/compiler/compiler.py

@@ -4,8 +4,8 @@
 import atexit
 import functools
 import logging
-import os
 import signal
+import subprocess
 import sys
 import time
 import uuid
@@ -125,12 +125,16 @@ def _start_server(
         params = f'{num_workers}, {runtime_log_level}, {worker_port=}'
         import_str = 'from bqskit.runtime.attached import start_attached_server'
         launch_str = f'{import_str}; start_attached_server({params})'
-        self.p = Popen([sys.executable, '-c', launch_str])
+        if sys.platform == 'win32':
+            flags = subprocess.CREATE_NEW_PROCESS_GROUP
+        else:
+            flags = 0
+        self.p = Popen([sys.executable, '-c', launch_str], creationflags=flags)
         _logger.debug('Starting runtime server process.')
 
     def _connect_to_server(self, ip: str, port: int) -> None:
         """Connect to a runtime server at `ip` and `port`."""
-        max_retries = 7
+        max_retries = 8
         wait_time = .25
         for _ in range(max_retries):
             try:
@@ -183,26 +187,35 @@ def close(self) -> None:
         # Shutdown server if attached
         if self.p is not None and self.p.pid is not None:
             try:
-                os.kill(self.p.pid, signal.SIGINT)
-                _logger.debug('Interrupted attached runtime server.')
-
+                if sys.platform == 'win32':
+                    self.p.send_signal(signal.CTRL_C_EVENT)
+                else:
+                    self.p.send_signal(signal.SIGINT)
+                _logger.debug('Interrupting attached runtime server.')
                 self.p.communicate(timeout=1)
-                if self.p.returncode is None:
-                    if sys.platform == 'win32':
-                        self.p.terminate()
-                    else:
-                        os.kill(self.p.pid, signal.SIGKILL)
-                    _logger.debug('Killed attached runtime server.')
+
+            except subprocess.TimeoutExpired:
+                self.p.kill()
+                _logger.debug('Killing attached runtime server.')
+                try:
+                    self.p.communicate(timeout=30)
+                except subprocess.TimeoutExpired:
+                    _logger.warning(
+                        'Failed to kill attached runtime server.'
+                        ' It may still be running as a zombie process.',
+                    )
+                else:
+                    _logger.debug('Attached runtime server is down.')
 
             except Exception as e:
-                _logger.debug(
+                _logger.warning(
                     f'Error while shuting down attached runtime server: {e}.',
                 )
+
             else:
                 _logger.debug('Successfully shutdown attached runtime server.')
+
             finally:
-                self.p.communicate()
-                _logger.debug('Attached runtime server is down.')
                 self.p = None
 
         # Reset interrupt signal handler and remove exit handler

bqskit/compiler/workflow.py

@@ -90,7 +90,7 @@ def name(self) -> str:
     def __str__(self) -> str:
         name_seq = f'Workflow: {self.name}\n\t'
         pass_strs = [
-            f'{i}. {'Workflow: ' + p.name if isinstance(p, Workflow) else p}'
+            f'{i}. Workflow: {p.name if isinstance(p, Workflow) else p}'
             for i, p in enumerate(self._passes)
         ]
         return name_seq + '\n\t'.join(pass_strs)

bqskit/passes/mapping/placement/trivial.py

@@ -20,7 +20,7 @@ async def run(self, circuit: Circuit, data: PassData) -> None:
         model = BasePass.get_model(circuit, data)
         data['placement'] = trivial_placement
 
-        _logger.info(f'Placed qudits on {data['placement']}')
+        _logger.info(f'Placed qudits on {data["placement"]}')
 
         # Raise an error if this is not a valid placement
         sg = model.coupling_graph.get_subgraph(data['placement'])

bqskit/passes/search/generators/fourparam.py

@@ -79,7 +79,9 @@ def gen_successors(self, circuit: Circuit, data: PassData) -> list[Circuit]:
 
             if self.count_outer_cnots(circuit, edge) >= 3:
                 # No need to build circuits with more than 3 cnots in a row
-                continue
+                if circuit.num_qudits != 2:
+                    # Guard on >2 qubit to prevent high-error glitches
+                    continue
 
             successor = circuit.copy()
             successor.append_gate(CNOTGate(), edge)

bqskit/version.py

@@ -1,4 +1,4 @@
 """This module contains the version information for BQSKit."""
 from __future__ import annotations
-__version_info__ = ('1', '1', '0')
+__version_info__ = ('1', '1', '1')
 __version__ = '.'.join(__version_info__[:3]) + ''.join(__version_info__[3:])

setup.py

@@ -66,7 +66,7 @@
     },
     packages=find_packages(exclude=['examples*', 'test*']),
     install_requires=[
-        'bqskitrs>=0.4.0',
+        'bqskitrs>=0.4.1',
         'lark-parser',
         'numpy>=1.22.0',
         'scipy>=1.8.0',

tests/compiler/compile/test_pam_verify.py

@@ -25,4 +25,6 @@ def test_pam_verify(compiler: Compiler, medium_qasm_file: str) -> None:
     PI = PermutationMatrix.from_qubit_location(out_circuit.num_qudits, pi)
     PF = PermutationMatrix.from_qubit_location(out_circuit.num_qudits, pf)
     exact_error = out_utry.get_distance_from(PF.T @ circuit.get_unitary() @ PI)
-    assert upper_bound_error >= exact_error or abs(upper_bound_error - exact_error) < 5e-7
+    assert upper_bound_error >= exact_error or abs(
+        upper_bound_error - exact_error,
+    ) < 5e-7

tests/compiler/compile/test_synthesis.py

@@ -154,8 +154,13 @@ def test_identity_synthesis(
     assert out_circuit.get_unitary().get_distance_from(
         UnitaryMatrix.identity(dim), 1,
     ) < 1e-8
-    if optimization_level == 3:
-        assert out_circuit.num_operations <= 3
+
+    # TODO: Re-enable this check when tree gate deletion hits the OTS.
+    # In cases where the identity is synthesized to two cnots surrounded
+    # by a bunch of single-qudit gates, scanning gate removal cannot
+    # remove either cnot.
+    # if optimization_level >= 3:
+    #     assert out_circuit.num_operations <= 3
 
 
 @pytest.mark.parametrize('num_qudits', [1, 2])