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

[Gaëtan Bossu via llvm-commits]

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@@ -17338,7 +17466,18 @@ class BoUpSLP::ShuffleInstructionBuilder final : public BaseShuffleAnalysis {
       });
       InVectors.front() = Vec;
     }
-    if (!SubVectors.empty()) {
+    if (SubVectors.size() == 1 && SubVectors.front().second == 0 &&
+        SubVectors.front().first->getVectorFactor() == CommonMask.size()) {
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gbossu wrote:

Nit: Same here: would be nice to give a name to that condition.

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