[llvm] [MSSAUpdater] Replace recursion with worklist and cap it. (PR #150543)

[Alina Sbirlea via llvm-commits]

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@@ -230,9 +223,61 @@ MemoryAccess *MemorySSAUpdater::tryRemoveTrivialPhi(MemoryPhi *Phi,
     removeMemoryAccess(Phi);
   }
 
-  // We should only end up recursing in case we replaced something, in which
-  // case, we may have made other Phis trivial.
-  return recursePhi(Same);
+  // Continue traversal in a DFS worklist approach, in case we might find
+  // other trivial Phis.
+  if (!Same)
+    return nullptr;
+
+  TrackingVH<MemoryAccess> Result(Same);
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alinas wrote:

I pushed a change that I think resolves this. PTAL?

https://github.com/llvm/llvm-project/pull/150543