[llvm] [VPlan] Handle early exit before forming regions. (NFC) (PR #138393)

[via llvm-commits]

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@@ -9383,7 +9383,8 @@ LoopVectorizationPlanner::tryToBuildVPlanWithVPRecipes(VFRange &Range) {
   VPlanTransforms::prepareForVectorization(
       *Plan, Legal->getWidestInductionType(), PSE, RequiresScalarEpilogueCheck,
       CM.foldTailByMasking(), OrigLoop,
-      getDebugLocFromInstOrOperands(Legal->getPrimaryInduction()));
+      getDebugLocFromInstOrOperands(Legal->getPrimaryInduction()),
+      Legal->hasUncountableEarlyExit(), Range);
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ayalz wrote:

Does passing `Legal->hasUncountableEarlyExit()` mean that (a) the loop has an uncountable early exit or (a+b) that this early exit should be sunk to the middle block - rather than (a+c: being sunk to the scalar remainder loop, i.e.,) leaving the last iteration be scalar?

https://github.com/llvm/llvm-project/pull/138393