Generic Qiskit Backend #722
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| ## | ||
| # Copyright (c) Microsoft Corporation. | ||
| # Licensed under the MIT License. | ||
| ## | ||
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| from __future__ import annotations | ||
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| from typing import TYPE_CHECKING, Any, Dict, Optional | ||
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| from azure.quantum.version import __version__ | ||
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| try: | ||
| from qiskit.providers import Options | ||
| from qsharp import TargetProfile | ||
| except ImportError as exc: | ||
| raise ImportError( | ||
| "Missing optional 'qiskit' dependencies. \ | ||
| To install run: pip install azure-quantum[qiskit]" | ||
| ) from exc | ||
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| from .backend import AzureBackendConfig, AzureQirBackend | ||
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| if TYPE_CHECKING: | ||
| from azure.quantum.qiskit import AzureQuantumProvider | ||
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| _DEFAULT_SHOTS_COUNT = 500 | ||
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| class AzureGenericQirBackend(AzureQirBackend): | ||
| """Fallback QIR backend for arbitrary Azure Quantum workspace targets. | ||
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| This backend is created dynamically by :class:`~azure.quantum.qiskit.provider.AzureQuantumProvider` | ||
| for targets present in the workspace that do not have a dedicated Qiskit backend class. | ||
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| It submits Qiskit circuits using QIR (`qir.v1`) payloads. | ||
| """ | ||
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| _SHOTS_PARAM_NAME = "shots" | ||
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| def __init__( | ||
| self, | ||
| name: str, | ||
| provider: "AzureQuantumProvider", | ||
| *, | ||
| provider_id: str, | ||
| target_profile: Optional[TargetProfile | str] = None, | ||
| num_qubits: Optional[int] = None, | ||
| description: Optional[str] = None, | ||
| **kwargs: Any, | ||
| ): | ||
| self._provider_id = provider_id | ||
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| config = AzureBackendConfig.from_dict( | ||
| { | ||
| "backend_name": name, | ||
| "backend_version": __version__, | ||
| "simulator": False, | ||
| "local": False, | ||
| "coupling_map": None, | ||
| "description": description | ||
| or f"Azure Quantum target '{name}' (generic QIR backend)", | ||
| "basis_gates": self._basis_gates(), | ||
| "memory": False, | ||
| "n_qubits": num_qubits, | ||
| "conditional": False, | ||
| "max_shots": None, | ||
| "open_pulse": False, | ||
| "gates": [{"name": "TODO", "parameters": [], "qasm_def": "TODO"}], | ||
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| "azure": self._azure_config(), | ||
| } | ||
| ) | ||
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| super().__init__(config, provider, **kwargs) | ||
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| # Prefer an instance-specific target profile discovered from the workspace target metadata. | ||
| default_target_profile = self._coerce_target_profile(target_profile) | ||
| if default_target_profile is not None: | ||
| self.set_options(target_profile=default_target_profile) | ||
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| @staticmethod | ||
| def _coerce_target_profile( | ||
| value: Optional[TargetProfile | str], | ||
| ) -> Optional[TargetProfile]: | ||
| if value is None: | ||
| return None | ||
| if isinstance(value, TargetProfile): | ||
| return value | ||
| if not isinstance(value, str): | ||
| return None | ||
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| raw = value.strip() | ||
| if not raw: | ||
| return None | ||
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| # Prefer the qsharp helper when available. | ||
| from_str = getattr(TargetProfile, "from_str", None) | ||
| if callable(from_str): | ||
| try: | ||
| parsed = from_str(raw) | ||
| if isinstance(parsed, TargetProfile): | ||
| return parsed | ||
| except Exception: | ||
| pass | ||
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| # Best-effort: try enum attribute lookup. | ||
| normalized = raw.replace("-", "_") | ||
| return getattr(TargetProfile, normalized, None) | ||
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| @classmethod | ||
| def _default_options(cls) -> Options: | ||
| # Default to the most conservative QIR profile; users can override per-run via | ||
| # `target_profile=` in backend.run(...). | ||
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Comment on lines
+112
to
+113
Contributor
Author
There was a problem hiding this comment. I believe you are referring to users' ability to set the target profile via
Contributor
There was a problem hiding this comment. The difference is that the default profile for backends always matched is capabilities. In this case the opposite is true. We don't know its caps and they don't necessarily match.
Contributor
Author
There was a problem hiding this comment. I see, you were asking about how users will know that the generic backends will default to the base profile. I'm not sure there is a specific way to do this, other than perhaps in the doc string for the generic backend class.
Contributor
Author
There was a problem hiding this comment. Though that idea would still have the target_profile here in this _default_options class method set to Base, as we can't use instance specific data here.
Contributor
Author
There was a problem hiding this comment. I've updated to take the target profile from the wrapped target's status. It will set the target_profile in the backend's |
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| return Options( | ||
| **{cls._SHOTS_PARAM_NAME: _DEFAULT_SHOTS_COUNT}, | ||
| target_profile=TargetProfile.Base, | ||
| ) | ||
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| def _azure_config(self) -> Dict[str, str]: | ||
| config = super()._azure_config() | ||
| config.update({"provider_id": self._provider_id, "is_default": False}) | ||
| return config | ||
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Where did this number come from? I tried looking in the backend base and the default was
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All of the other backends use 500 as their default shot count, so it seemed appropriate to follow suit here.