[llvm] [DAG] Combine `store + vselect` to `masked_store` (PR #145176)

[Simon Pilgrim via llvm-commits]

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@@ -22488,12 +22488,53 @@ SDValue DAGCombiner::visitATOMIC_STORE(SDNode *N) {
   return SDValue();
 }
 
+static SDValue foldToMaskedStore(StoreSDNode *Store, SelectionDAG &DAG,
+                                 const SDLoc &Dl) {
+  using namespace llvm::SDPatternMatch;
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RKSimon wrote:

isNormalStore?

https://github.com/llvm/llvm-project/pull/145176