[mlir][python] enable registering dialects with the default Context (#72488)

Author: makslevental

mlir/python/mlir/_mlir_libs/__init__.py

@@ -56,14 +56,28 @@ def get_include_dirs() -> Sequence[str]:
 #
 # This facility allows downstreams to customize Context creation to their
 # needs.
+
+_dialect_registry = None
+
+
+def get_dialect_registry():
+    global _dialect_registry
+
+    if _dialect_registry is None:
+        from ._mlir import ir
+
+        _dialect_registry = ir.DialectRegistry()
+
+    return _dialect_registry
+
+
 def _site_initialize():
     import importlib
     import itertools
     import logging
     from ._mlir import ir
 
     logger = logging.getLogger(__name__)
-    registry = ir.DialectRegistry()
     post_init_hooks = []
     disable_multithreading = False
 
@@ -84,7 +98,7 @@ def process_initializer_module(module_name):
         logger.debug("Initializing MLIR with module: %s", module_name)
         if hasattr(m, "register_dialects"):
             logger.debug("Registering dialects from initializer %r", m)
-            m.register_dialects(registry)
+            m.register_dialects(get_dialect_registry())
         if hasattr(m, "context_init_hook"):
             logger.debug("Adding context init hook from %r", m)
             post_init_hooks.append(m.context_init_hook)
@@ -110,7 +124,7 @@ def process_initializer_module(module_name):
     class Context(ir._BaseContext):
         def __init__(self, *args, **kwargs):
             super().__init__(*args, **kwargs)
-            self.append_dialect_registry(registry)
+            self.append_dialect_registry(get_dialect_registry())
             for hook in post_init_hooks:
                 hook(self)
             if not disable_multithreading:

mlir/python/mlir/dialects/python_test.py

@@ -11,7 +11,7 @@
 )
 
 
-def register_python_test_dialect(context, load=True):
+def register_python_test_dialect(registry):
     from .._mlir_libs import _mlirPythonTest
 
-    _mlirPythonTest.register_python_test_dialect(context, load)
+    _mlirPythonTest.register_dialect(registry)

mlir/python/mlir/ir.py

@@ -5,6 +5,7 @@
 from ._mlir_libs._mlir.ir import *
 from ._mlir_libs._mlir.ir import _GlobalDebug
 from ._mlir_libs._mlir import register_type_caster, register_value_caster
+from ._mlir_libs import get_dialect_registry
 
 
 # Convenience decorator for registering user-friendly Attribute builders.

mlir/test/python/dialects/python_test.py

@@ -6,6 +6,8 @@
 import mlir.dialects.tensor as tensor
 import mlir.dialects.arith as arith
 
+test.register_python_test_dialect(get_dialect_registry())
+
 
 def run(f):
     print("\nTEST:", f.__name__)
@@ -17,7 +19,6 @@ def run(f):
 @run
 def testAttributes():
     with Context() as ctx, Location.unknown():
-        test.register_python_test_dialect(ctx)
         #
         # Check op construction with attributes.
         #
@@ -138,7 +139,6 @@ def testAttributes():
 @run
 def attrBuilder():
     with Context() as ctx, Location.unknown():
-        test.register_python_test_dialect(ctx)
         # CHECK: python_test.attributes_op
         op = test.AttributesOp(
             # CHECK-DAG: x_affinemap = affine_map<() -> (2)>
@@ -215,7 +215,6 @@ def attrBuilder():
 @run
 def inferReturnTypes():
     with Context() as ctx, Location.unknown(ctx):
-        test.register_python_test_dialect(ctx)
         module = Module.create()
         with InsertionPoint(module.body):
             op = test.InferResultsOp()
@@ -260,7 +259,6 @@ def inferReturnTypes():
 @run
 def resultTypesDefinedByTraits():
     with Context() as ctx, Location.unknown(ctx):
-        test.register_python_test_dialect(ctx)
         module = Module.create()
         with InsertionPoint(module.body):
             inferred = test.InferResultsOp()
@@ -295,8 +293,6 @@ def resultTypesDefinedByTraits():
 @run
 def testOptionalOperandOp():
     with Context() as ctx, Location.unknown():
-        test.register_python_test_dialect(ctx)
-
         module = Module.create()
         with InsertionPoint(module.body):
             op1 = test.OptionalOperandOp()
@@ -312,7 +308,6 @@ def testOptionalOperandOp():
 @run
 def testCustomAttribute():
     with Context() as ctx:
-        test.register_python_test_dialect(ctx)
         a = test.TestAttr.get()
         # CHECK: #python_test.test_attr
         print(a)
@@ -350,7 +345,6 @@ def testCustomAttribute():
 @run
 def testCustomType():
     with Context() as ctx:
-        test.register_python_test_dialect(ctx)
         a = test.TestType.get()
         # CHECK: !python_test.test_type
         print(a)
@@ -397,8 +391,6 @@ def testCustomType():
 # CHECK-LABEL: TEST: testTensorValue
 def testTensorValue():
     with Context() as ctx, Location.unknown():
-        test.register_python_test_dialect(ctx)
-
         i8 = IntegerType.get_signless(8)
 
         class Tensor(test.TestTensorValue):
@@ -436,7 +428,6 @@ def __str__(self):
 @run
 def inferReturnTypeComponents():
     with Context() as ctx, Location.unknown(ctx):
-        test.register_python_test_dialect(ctx)
         module = Module.create()
         i32 = IntegerType.get_signless(32)
         with InsertionPoint(module.body):
@@ -488,8 +479,6 @@ def inferReturnTypeComponents():
 @run
 def testCustomTypeTypeCaster():
     with Context() as ctx, Location.unknown():
-        test.register_python_test_dialect(ctx)
-
         a = test.TestType.get()
         assert a.typeid is not None
 
@@ -542,7 +531,6 @@ def type_caster(pytype):
 @run
 def testInferTypeOpInterface():
     with Context() as ctx, Location.unknown(ctx):
-        test.register_python_test_dialect(ctx)
         module = Module.create()
         with InsertionPoint(module.body):
             i64 = IntegerType.get_signless(64)

mlir/test/python/lib/PythonTestModule.cpp

@@ -34,6 +34,15 @@ PYBIND11_MODULE(_mlirPythonTest, m) {
       },
       py::arg("context"), py::arg("load") = true);
 
+  m.def(
+      "register_dialect",
+      [](MlirDialectRegistry registry) {
+        MlirDialectHandle pythonTestDialect =
+            mlirGetDialectHandle__python_test__();
+        mlirDialectHandleInsertDialect(pythonTestDialect, registry);
+      },
+      py::arg("registry"));
+
   mlir_attribute_subclass(m, "TestAttr",
                           mlirAttributeIsAPythonTestTestAttribute)
       .def_classmethod(