Create xDSL universe for the unified compiler

doc/releases/changelog-dev.md

@@ -632,6 +632,10 @@
 
 <h4>Other improvements</h4>
 
+* An xDSL `Universe` containing all custom dialects and passes has been registered as an entry point, allowing
+  usage of PennyLane's dialects and passes with xDSL's command-line tools
+  [(#8372)](https://github.com/PennyLaneAI/pennylane/pull/8372)
+
 * Two new `draw` and `generate_mlir_graph` functions have been introduced in the `qml.compiler.python_compiler.visualization` module
   to visualize circuits with the new unified compiler framework when xDSL and/or Catalyst compilation passes are applied.
   [(#8040)](https://github.com/PennyLaneAI/pennylane/pull/8040)

pennylane/compiler/python_compiler/__init__.py

@@ -13,11 +13,19 @@
 # limitations under the License.
 """Python Compiler API for integration of Catalyst with xDSL."""
 
+from xdsl.universe import Universe
+
 from .compiler import Compiler
 from .parser import QuantumParser
 from .pass_api import compiler_transform
 from .visualization import QMLCollector
 
+from .dialects import get_universe_dialects
+from .transforms import get_universe_passes
+
+# Universe is used to expose custom dialects and transforms to xDSL
+XDSL_UNIVERSE = Universe(all_dialects=get_universe_dialects(), all_passes=get_universe_passes())
+
 
 __all__ = [
     "Compiler",

pennylane/compiler/python_compiler/dialects/__init__.py

@@ -22,4 +22,20 @@
 from .transform import Transform
 
 
+def get_universe_dialects():
+    """Get a mapping between all available dialect names to dialect classes. This
+    is used to initialize the PennyLane-xDSL universe, which is needed to make the
+    dialects readily available to xDSL command-line tools."""
+    return {
+        "catalyst": Catalyst,
+        "mbqc": MBQC,
+        "quantum": Quantum,
+        "qec": QEC,
+        # Dialects available in xDSL already cannot be added to the universe, since
+        # the "multiverse" cannot have duplicate dialects
+        # "stablehlo": StableHLO,
+        # "transform": Transform,
+    }
+
+
 __all__ = ["Catalyst", "MBQC", "Quantum", "QEC", "StableHLO", "Transform"]

pennylane/compiler/python_compiler/transforms/__init__.py

@@ -36,6 +36,22 @@
 )
 
 
+def get_universe_passes():
+    """Get a mapping between all available pass names to pass classes. This is used
+    to initialize the PennyLane-xDSL universe, which is needed to make the passes
+    readily available to xDSL command-line tools."""
+    return {
+        "combine-global-phases": CombineGlobalPhasesPass,
+        "convert-to-mbqc-formalism": ConvertToMBQCFormalismPass,
+        "decompose-graph-state": DecomposeGraphStatePass,
+        "diagonalize-final-measurements": DiagonalizeFinalMeasurementsPass,
+        "xdsl-cancel-inverses": IterativeCancelInversesPass,
+        "measurements-from-samples": MeasurementsFromSamplesPass,
+        "xdsl-merge-rotations": MergeRotationsPass,
+        "null-decompose-graph-state": NullDecomposeGraphStatePass,
+    }
+
+
 __all__ = [
     # Quantum
     "combine_global_phases_pass",

pyproject.toml

@@ -68,6 +68,9 @@ pl-device-test = "pennylane.devices.tests:cli"
 "default.qutrit.mixed" = "pennylane.devices.default_qutrit_mixed:DefaultQutritMixed"
 "default.tensor" = "pennylane.devices.default_tensor:DefaultTensor"
 
+[project.entry-points."xdsl.universe"]
+"pennylane" = "pennylane.compiler.python_compiler:XDSL_UNIVERSE"
+
 [project.entry-points."console_scripts"]
 "pl-device-test" = "pennylane.devices.tests:cli"