[llvm] [DAGCombiner] Turn `(neg (max x, (neg x)))` into `(min x, (neg x))` (PR #120666)

[Min-Yih Hsu via llvm-commits]

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@@ -3949,6 +3949,20 @@ SDValue DAGCombiner::visitSUB(SDNode *N) {
       if (SDValue Result = TLI.expandABS(N1.getNode(), DAG, true))
         return Result;
 
+    // Similar to the previous rule, but this time targeting an expanded abs.
+    // (sub 0, (max X, (sub 0, X))) --> (min X, (sub 0, X))
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mshockwave wrote:

I think it's fine to add it in this patch. It's done now.

https://github.com/llvm/llvm-project/pull/120666