[llvm] [AArch64][SVE2] Use rshrnb for masked stores (PR #70026)

[Matthew Devereau via llvm-commits]

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@@ -21017,6 +21017,21 @@ static SDValue performMSTORECombine(SDNode *N,
     }
   }
 
+  if (MST->isTruncatingStore()) {
+    if (SDValue Rshrnb = trySimplifySrlAddToRshrnb(Value, DAG, Subtarget)) {
+      EVT ValueVT = Value->getValueType(0);
+      EVT MemVT = MST->getMemoryVT();
+      if ((ValueVT == MVT::nxv8i16 && MemVT == MVT::nxv8i8) ||
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MDevereau wrote:

Done!

https://github.com/llvm/llvm-project/pull/70026