[llvm] [LV] Factor costInterleaveGatherScatter (NFC) (PR #215857)

[Ramkumar Ramachandra via llvm-commits]

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@@ -4416,50 +4485,13 @@ void LoopVectorizationCostModel::setCostBasedWideningDecision(ElementCount VF) {
       if (!Ptr)
         continue;
 
+      // Choose between Interleaving, Gather/Scatter or Scalarization.
+      auto [Decision, Cost] = costInterleaveGatherScatter(&I, VF);
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artagnon wrote:

Ah, but the later hunk runs it unconditionally anyway, and we're simply sharing the conditional and unconditional calls?

https://github.com/llvm/llvm-project/pull/215857