[llvm] [LV] Change opcode of FindLast/FindFirst recurrence to Instruction::Select (PR #162252)

[Florian Hahn via llvm-commits]

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@@ -6515,9 +6515,14 @@ void LoopVectorizationCostModel::collectInLoopReductions() {
     if (RdxDesc.getRecurrenceType() != Phi->getType())
       continue;
 
+    // In-loop AnyOf and FindIV reductions are not yet supported.
+    RecurKind Kind = RdxDesc.getRecurrenceKind();
+    if (RecurrenceDescriptor::isAnyOfRecurrenceKind(Kind) ||
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fhahn wrote:

With this change, can we make Find* `unreachable` in `getOpcode` for now?

https://github.com/llvm/llvm-project/pull/162252