[llvm] [VPlan] Introduce explicit ExtractFromEnd recipes for live-outs. (PR #100658)

[via llvm-commits]

================
@@ -8470,22 +8480,29 @@ static void addUsersInExitBlock(
     // live-outs.
     if ((isa<VPWidenIntOrFpInductionRecipe>(V) &&
          !cast<VPWidenIntOrFpInductionRecipe>(V)->getTruncInst()) ||
-        isa<VPWidenPointerInductionRecipe>(V) ||
+        isa<VPWidenPointerInductionRecipe, VPFirstOrderRecurrencePHIRecipe>(
----------------
ayalz wrote:

Wonder if it would be better to maintain an ExitingValuesToFix list, similar to [Header]PhisToFix, where induction (w/o truncates) or FORs that are dealt with elsewhere take themselves off the list, followed by the general extract-last treatment applied here to all remaining ones, rather than trying to identify here all cases treated elsewhere only to skip them.

https://github.com/llvm/llvm-project/pull/100658