[llvm] [X86] combineConstantPoolLoads - correctly merge constant pool loads by pointer and chain (PR #139575)

[Phoebe Wang via llvm-commits]

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@@ -52902,6 +52902,7 @@ static SDValue combineConstantPoolLoads(SDNode *N, const SDLoc &dl,
               getTargetConstantBitsFromNode(SDValue(User, 0), NumBits,
                                             UserUndefs, UserBits)) {
             if (MatchingBits(Undefs, UserUndefs, Bits, UserBits)) {
+              DAG.makeEquivalentMemoryOrdering(SDValue(N, 1), SDValue(User, 1));
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phoebewang wrote:

Why we care about the order since they have the same intput chain?

https://github.com/llvm/llvm-project/pull/139575