[Mlir-commits] [mlir] [mlir][CSE] Add remove dominanceInfo to CSE (PR #192279)

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<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-mlir

Author: lonely eagle (linuxlonelyeagle)

<details>
<summary>Changes</summary>

The CSE pass calls `markAnalysesPreserved<DominanceInfo, PostDominanceInfo>()` at the end. While CSE erases operations, it does not remove their corresponding dominator trees, causing them to be unnecessarily preserved in memory. This PR addresses the issue by explicitly calling invalidate within CSE to clean up the dominator trees for those erased operations.

---
Full diff: https://github.com/llvm/llvm-project/pull/192279.diff


1 Files Affected:

- (modified) mlir/lib/Transforms/CSE.cpp (+6-2) 


``````````diff
diff --git a/mlir/lib/Transforms/CSE.cpp b/mlir/lib/Transforms/CSE.cpp
index 4d25e5e7c92b6..fbd9e45cc1955 100644
--- a/mlir/lib/Transforms/CSE.cpp
+++ b/mlir/lib/Transforms/CSE.cpp
@@ -394,9 +394,13 @@ void CSEDriver::simplify(Operation *op, bool *changed) {
   for (auto &region : op->getRegions())
     simplifyRegion(knownValues, region);
 
-  /// Erase any operations that were marked as dead during simplification.
-  for (auto *op : opsToErase)
+  /// Erase any operations that were marked as dead during simplification, and
+  /// remove their associated dominator trees.
+  for (auto *op : opsToErase) {
+    for (Region &region : op->getRegions())
+      domInfo->invalidate(&region);
     rewriter.eraseOp(op);
+  }
   if (changed)
     *changed = !opsToErase.empty();
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/192279