[Mlir-commits] [mlir] [mlir][python, CAPI] expose Op::isBeforeInBlock (PR #150271)

[Maksim Levental]

https://github.com/makslevental created https://github.com/llvm/llvm-project/pull/150271

None

>From 936f23553dbb430c9c537723b67cdb0efbef2737 Mon Sep 17 00:00:00 2001
From: max <maksim.levental at gmail.com>
Date: Wed, 23 Jul 2025 13:14:51 -0400
Subject: [PATCH] [mlir][python,CAPI] expose Op::isBeforeInBlock

---
 mlir/include/mlir-c/IR.h            |  7 +++++++
 mlir/lib/Bindings/Python/IRCore.cpp | 15 +++++++++++++++
 mlir/lib/Bindings/Python/IRModule.h |  7 +++++++
 mlir/lib/CAPI/IR/IR.cpp             |  4 ++++
 mlir/test/python/ir/operation.py    |  4 ++++
 5 files changed, 37 insertions(+)

diff --git a/mlir/include/mlir-c/IR.h b/mlir/include/mlir-c/IR.h
index 81299c7911d24..71c7d4378677f 100644
--- a/mlir/include/mlir-c/IR.h
+++ b/mlir/include/mlir-c/IR.h
@@ -813,6 +813,13 @@ MLIR_CAPI_EXPORTED void mlirOperationMoveAfter(MlirOperation op,
 MLIR_CAPI_EXPORTED void mlirOperationMoveBefore(MlirOperation op,
                                                 MlirOperation 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.
+MLIR_CAPI_EXPORTED bool mlirOperationIsBeforeInBlock(MlirOperation op,
+                                                     MlirOperation other);
 /// Operation walk result.
 typedef enum MlirWalkResult {
   MlirWalkResultAdvance,
diff --git a/mlir/lib/Bindings/Python/IRCore.cpp b/mlir/lib/Bindings/Python/IRCore.cpp
index 7b790e90e0d87..5feed95f96f53 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 0fdd2d1a7eff6..9c22dea157c06 100644
--- a/mlir/lib/Bindings/Python/IRModule.h
+++ b/mlir/lib/Bindings/Python/IRModule.h
@@ -624,6 +624,13 @@ class PyOperationBase {
   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();
diff --git a/mlir/lib/CAPI/IR/IR.cpp b/mlir/lib/CAPI/IR/IR.cpp
index fbc66bcf5c2d0..8491553dab76f 100644
--- a/mlir/lib/CAPI/IR/IR.cpp
+++ b/mlir/lib/CAPI/IR/IR.cpp
@@ -850,6 +850,10 @@ void mlirOperationMoveBefore(MlirOperation op, MlirOperation other) {
   return unwrap(op)->moveBefore(unwrap(other));
 }
 
+bool mlirOperationIsBeforeInBlock(MlirOperation op, MlirOperation other) {
+  return unwrap(op)->isBeforeInBlock(unwrap(other));
+}
+
 static mlir::WalkResult unwrap(MlirWalkResult result) {
   switch (result) {
   case MlirWalkResultAdvance:
diff --git a/mlir/test/python/ir/operation.py b/mlir/test/python/ir/operation.py
index ede1571f940f6..c6b5dafe792ca 100644
--- a/mlir/test/python/ir/operation.py
+++ b/mlir/test/python/ir/operation.py
@@ -978,8 +978,12 @@ def testModuleMerge():
         foo = m1.body.operations[0]
         bar = m2.body.operations[0]
         qux = m2.body.operations[1]
+        assert bar.is_before_in_block(qux)
         bar.move_before(foo)
+        assert bar.is_before_in_block(foo)
         qux.move_after(foo)
+        assert bar.is_before_in_block(qux)
+        assert foo.is_before_in_block(qux)
 
         # CHECK: module
         # CHECK: func private @bar