[llvm] [Reassociate] Preserve NUW flags after expr tree rewriting (PR #72360)

[Yingwei Zheng via llvm-commits]

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@@ -1225,7 +1234,7 @@ Value *ReassociatePass::RemoveFactorFromExpression(Value *V, Value *Factor) {
     RedoInsts.insert(BO);
     V = Factors[0].Op;
   } else {
-    RewriteExprTree(BO, Factors);
+    RewriteExprTree(BO, Factors, HasNUW);
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dtcxzyw wrote:

I don't think it is an issue.
The transform `-C *nuw X1 *nuw X2 *nuw X3` --> `C * -(X1 *nuw X2 *nuw X3)` is correct.

https://github.com/llvm/llvm-project/pull/72360