[llvm] [VPlan] Transform VPFirstOrderRecurrencePHIRecipe into concrete recipes (PR #172009)

[Florian Hahn via llvm-commits]

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@@ -3695,6 +3695,34 @@ void VPlanTransforms::convertToConcreteRecipes(VPlan &Plan) {
         continue;
       }
 
+      if (auto *FORPhiR = dyn_cast<VPFirstOrderRecurrencePHIRecipe>(&R)) {
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fhahn wrote:

Would be good to document the expansion here briefly

https://github.com/llvm/llvm-project/pull/172009