Move condition that checks whether current reduction is a a partial

reduction.

Author: JamesChesterman

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -9728,7 +9728,8 @@ void LoopVectorizationPlanner::adjustRecipesForReductions(
     // beginning of the dedicated latch block.
     auto *OrigExitingVPV = PhiR->getBackedgeValue();
     auto *NewExitingVPV = PhiR->getBackedgeValue();
-    if (!PhiR->isInLoop() && CM.foldTailByMasking()) {
+    if (!PhiR->isInLoop() && CM.foldTailByMasking() &&
+        !isa<VPPartialReductionRecipe>(OrigExitingVPV->getDefiningRecipe())) {
       VPValue *Cond = RecipeBuilder.getBlockInMask(OrigLoop->getHeader());
       assert(OrigExitingVPV->getDefiningRecipe()->getParent() != LatchVPBB &&
              "reduction recipe must be defined before latch");
@@ -9737,9 +9738,8 @@ void LoopVectorizationPlanner::adjustRecipesForReductions(
           PhiTy->isFloatingPointTy()
               ? std::make_optional(RdxDesc.getFastMathFlags())
               : std::nullopt;
-      if (!isa<VPPartialReductionRecipe>(OrigExitingVPV->getDefiningRecipe()))
-        NewExitingVPV =
-            Builder.createSelect(Cond, OrigExitingVPV, PhiR, {}, "", FMFs);
+      NewExitingVPV =
+          Builder.createSelect(Cond, OrigExitingVPV, PhiR, {}, "", FMFs);
       OrigExitingVPV->replaceUsesWithIf(NewExitingVPV, [](VPUser &U, unsigned) {
         return isa<VPInstruction>(&U) &&
                cast<VPInstruction>(&U)->getOpcode() ==