[llvm] [SLP] Check for extracts, being replaced by original scalars, for user nodes (PR #149572)

[Gaëtan Bossu via llvm-commits]

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@@ -10689,6 +10778,17 @@ void BoUpSLP::buildTreeRec(ArrayRef<Value *> VLRef, unsigned Depth,
     return;
   }
 
+  // Postpone vectorization, if the node is not profitable because of the
+  // external uses.
+  if (!isProfitableToVectorizeWithNonVecUsers(S, UserTreeIdx, VL,
+                                              ReuseShuffleIndices)) {
+    PostponedNodesWithNonVecUsers.insert(VectorizableTree.size());
+    auto Invalid = ScheduleBundle::invalid();
+    newTreeEntry(VL, Invalid /*not vectorized*/, S, UserTreeIdx,
+                 ReuseShuffleIndices);
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gbossu wrote:

Nit: Could you use `newGatherTreeEntry(VL, S, UserTreeIdx, ReuseShuffleIndices);` instead?

https://github.com/llvm/llvm-project/pull/149572