[llvm] [SelectionDAG][PowerPC] Remove setTruncatingStore from StoreSDNode. (PR #137667)

[Sergei Barannikov via llvm-commits]

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@@ -16562,13 +16562,16 @@ SDValue PPCTargetLowering::PerformDAGCombine(SDNode *N,
                                     MemVT.getSizeInBits());
       SDValue Const64 = DAG.getConstant(Val64, dl, MVT::i64);
 
-      // DAG.getTruncStore() can't be used here because it doesn't accept
-      // the general (base + offset) addressing mode.
-      // So we use UpdateNodeOperands and setTruncatingStore instead.
-      DAG.UpdateNodeOperands(N, N->getOperand(0), Const64, N->getOperand(2),
-                             N->getOperand(3));
-      cast<StoreSDNode>(N)->setTruncatingStore(true);
-      return SDValue(N, 0);
+      auto *ST = cast<StoreSDNode>(N);
+      SDValue NewST = DAG.getStore(ST->getChain(), dl, Const64,
+                                   ST->getBasePtr(), ST->getOffset(), MemVT,
+                                   ST->getMemOperand(), ST->getAddressingMode(),
+                                   /*IsTruncating=*/true);
+      // Note we use CombineTo here to prevent DAGCombine from visiting the
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s-barannikov wrote:

```suggestion
      // Note we use CombineTo here to prevent DAGCombiner from visiting the
```

https://github.com/llvm/llvm-project/pull/137667