3 files changed, 32 insertions, 3 deletions
diff --git a/mlir/lib/Bindings/Python/IRAttributes.cpp b/mlir/lib/Bindings/Python/IRAttributes.cpp
index 8f79caf..db84ee1 100644
--- a/mlir/lib/Bindings/Python/IRAttributes.cpp
+++ b/mlir/lib/Bindings/Python/IRAttributes.cpp
@@ -16,8 +16,8 @@
 #include "NanobindUtils.h"
 #include "mlir-c/BuiltinAttributes.h"
 #include "mlir-c/BuiltinTypes.h"
-#include "mlir/Bindings/Python/NanobindAdaptors.h"
 #include "mlir/Bindings/Python/Nanobind.h"
+#include "mlir/Bindings/Python/NanobindAdaptors.h"
 #include "llvm/ADT/ScopeExit.h"
 #include "llvm/Support/raw_ostream.h"
 
@@ -1428,6 +1428,12 @@ public:
   }
 };
 
+// Check if the python version is less than 3.13. Py_IsFinalizing is a part
+// of stable ABI since 3.13 and before it was available as _Py_IsFinalizing.
+#if PY_VERSION_HEX < 0x030d0000
+#define Py_IsFinalizing _Py_IsFinalizing
+#endif
+
 class PyDenseResourceElementsAttribute
     : public PyConcreteAttribute<PyDenseResourceElementsAttribute> {
 public:
@@ -1474,8 +1480,9 @@ public:
     // The userData is a Py_buffer* that the deleter owns.
     auto deleter = [](void *userData, const void *data, size_t size,
                       size_t align) {
-      if (!Py_IsInitialized())
-        Py_Initialize();
+      if (Py_IsFinalizing())
+        return;
+      assert(Py_IsInitialized() && "expected interpreter to be initialized");
       Py_buffer *ownedView = static_cast<Py_buffer *>(userData);
       nb::gil_scoped_acquire gil;
       PyBuffer_Release(ownedView);
diff --git a/mlir/lib/Bindings/Python/IRCore.cpp b/mlir/lib/Bindings/Python/IRCore.cpp
index 7b790e9..5feed95 100644
--- a/mlir/lib/Bindings/Python/IRCore.cpp
+++ b/mlir/lib/Bindings/Python/IRCore.cpp
@@ -1454,6 +1454,14 @@ void PyOperationBase::moveBefore(PyOperationBase &other) {
   operation.parentKeepAlive = otherOp.parentKeepAlive;
 }
 
+bool PyOperationBase::isBeforeInBlock(PyOperationBase &other) {
+  PyOperation &operation = getOperation();
+  PyOperation &otherOp = other.getOperation();
+  operation.checkValid();
+  otherOp.checkValid();
+  return mlirOperationIsBeforeInBlock(operation, otherOp);
+}
+
 bool PyOperationBase::verify() {
   PyOperation &op = getOperation();
   PyMlirContext::ErrorCapture errors(op.getContext());
@@ -3409,6 +3417,13 @@ void mlir::python::populateIRCore(nb::module_ &m) {
       .def("move_before", &PyOperationBase::moveBefore, nb::arg("other"),
            "Puts self immediately before the other operation in its parent "
            "block.")
+      .def("is_before_in_block", &PyOperationBase::isBeforeInBlock,
+           nb::arg("other"),
+           "Given an operation 'other' that is within the same parent block, "
+           "return"
+           "whether the current operation is before 'other' in the operation "
+           "list"
+           "of the parent block.")
       .def(
           "clone",
           [](PyOperationBase &self, nb::object ip) {
diff --git a/mlir/lib/Bindings/Python/IRModule.h b/mlir/lib/Bindings/Python/IRModule.h
index 0fdd2d1..9c22dea 100644
--- a/mlir/lib/Bindings/Python/IRModule.h
+++ b/mlir/lib/Bindings/Python/IRModule.h
@@ -624,6 +624,13 @@ public:
   void moveAfter(PyOperationBase &other);
   void moveBefore(PyOperationBase &other);
 
+  /// Given an operation 'other' that is within the same parent block, return
+  /// whether the current operation is before 'other' in the operation list
+  /// of the parent block.
+  /// Note: This function has an average complexity of O(1), but worst case may
+  /// take O(N) where N is the number of operations within the parent block.
+  bool isBeforeInBlock(PyOperationBase &other);
+
   /// Verify the operation. Throws `MLIRError` if verification fails, and
   /// returns `true` otherwise.
   bool verify();