add fusion cost tuning

qiskit/providers/aer/backends/aerbackend.py

@@ -237,14 +237,21 @@ def _run_job(self, job_id, qobj, backend_options, noise_model, validate):
         # Add default OpenMP options
         if 'statevector_parallel_threshold' not in backend_options and hasattr(
                 self, '_statevector_parallel_threshold'):
-            backend_options['statevector_parallel_threshold'] = self._statevector_parallel_threshold
+            backend_options['statevector_parallel_threshold'] = \
+                getattr(self, '_statevector_parallel_threshold')
 
         # Add default fusion options
         attr_postfix = '_gpu' if 'gpu' in backend_options.get('method', '') else ''
         if 'fusion_threshold' not in backend_options and hasattr(
-            self, f'_fusion_threshold{attr_postfix}'):
+                self, f'_fusion_threshold{attr_postfix}'):
             # Set fusion threshold
             backend_options['fusion_threshold'] = getattr(self, f'_fusion_threshold{attr_postfix}')
+        for i in range(1, 6):
+            if f'fusion_cost.{i}' not in backend_options and \
+               hasattr(self, f'_fusion_cost{attr_postfix}.{i}'):
+                # Set cost for each
+                backend_options[f'fusion_cost.{i}'] = getattr(self,
+                                                              f'_fusion_cost{attr_postfix}.{i}')
 
         # The new function swaps positional args qobj and job id so we do a
         # type check to swap them back

qiskit/providers/aer/profile.py

@@ -13,8 +13,10 @@
 Profile backend options for optimal performance
 """
 from qiskit import transpile, assemble, execute
+from qiskit.circuit.library import QuantumVolume
 from .aererror import AerError
-
+from .backends.aerbackend import AerBackend
+from .backends.qasm_simulator import QasmSimulator
 
 def optimize_backend_options(min_qubits=10, max_qubits=20, ntrials=10):
     """Set optimal OpenMP and fusion options for backend."""
@@ -49,8 +51,6 @@ def optimize_backend_options(min_qubits=10, max_qubits=20, ntrials=10):
     # TODO: Write profile to a local qiskitaerrc file so this doesn't
     # need to be re-run on a system and the following can be loaded
     # in the AerBackend class from the rc file if it is found
-    from qiskit.providers.aer.backends.aerbackend import AerBackend
-
     if 'statevector_parallel_threshold' in profile:
         AerBackend._statevector_parallel_threshold = profile[
             'statevector_parallel_threshold']
@@ -66,9 +66,6 @@ def profile_parallel_threshold(min_qubits=10, max_qubits=20, ntrials=10,
                                backend_options=None,
                                return_ratios=False):
     """Evaluate optimal OMP parallel threshold for current system."""
-    from qiskit.circuit.library import QuantumVolume
-    from qiskit.providers.aer.backends.qasm_simulator import QasmSimulator
-
     simulator = QasmSimulator()
     opts = {'method': 'statevector',
             'max_parallel_experiments': 1,
@@ -123,9 +120,6 @@ def profile_fusion_threshold(min_qubits=10, max_qubits=20, ntrials=10,
                              backend_options=None, gpu=False,
                              return_ratios=False):
     """Evaluate optimal OMP parallel threshold for current system."""
-    from qiskit.circuit.library import QuantumVolume
-    from qiskit.providers.aer.backends.qasm_simulator import QasmSimulator
-
     simulator = QasmSimulator()
     opts = {'method': 'statevector',
             'max_parallel_experiments': 1,