[llvm] [LoopVectorize] Further improve cost model for early exit loops (PR #126235)

[Florian Hahn via llvm-commits]

================
@@ -10564,12 +10591,17 @@ bool LoopVectorizePass::processLoop(Loop *L) {
     if (VF.Width.isVector() || SelectedIC > 1)
       Checks.create(L, *LVL.getLAI(), PSE.getPredicate(), VF.Width, SelectedIC);
 
+    InstructionCost EarlyExitCost = InstructionCost::getInvalid();
+    if (VF.Width.isVector() && LVL.hasUncountableEarlyExit())
+      EarlyExitCost =
+          calculateEarlyExitCost(CM, LVP.getPlanFor(VF.Width), VF.Width);
----------------
fhahn wrote:

Would it be possible to instead pass the plan to `isOutsideLoopWorkProfitable` and compute the cost if needed there? 

https://github.com/llvm/llvm-project/pull/126235