diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -1594,11 +1594,6 @@
     return InLoopReductionChains;
   }
 
-  /// Returns true if the Phi is part of an inloop reduction.
-  bool isInLoopReduction(PHINode *Phi) const {
-    return InLoopReductionChains.count(Phi);
-  }
-
   /// Estimate cost of an intrinsic call instruction CI if it were vectorized
   /// with factor VF.  Return the cost of the instruction, including
   /// scalarization overhead if it's needed.
@@ -4308,7 +4303,7 @@
   TrackingVH<Value> ReductionStartValue = RdxDesc.getRecurrenceStartValue();
   Instruction *LoopExitInst = RdxDesc.getLoopExitInstr();
   setDebugLocFromInst(Builder, ReductionStartValue);
-  bool IsInLoopReductionPhi = Cost->isInLoopReduction(OrigPhi);
+  bool IsInLoopReductionPhi = PhiR->isInLoopReduction();
 
   VPValue *LoopExitInstDef = State.Plan->getVPValue(LoopExitInst);
   // This is the vector-clone of the value that leaves the loop.
@@ -4723,8 +4718,8 @@
   // this value when we vectorize all of the instructions that use the PHI.
   if (RdxDesc || Legal->isFirstOrderRecurrence(P)) {
     Value *Iden = nullptr;
-    bool ScalarPHI =
-        (State.VF.isScalar()) || Cost->isInLoopReduction(cast<PHINode>(PN));
+    bool IsInLoopReduction = PhiR->isInLoopReduction();
+    bool ScalarPHI = State.VF.isScalar() || IsInLoopReduction;
     Type *VecTy =
         ScalarPHI ? PN->getType() : VectorType::get(PN->getType(), State.VF);
 
@@ -4758,8 +4753,7 @@
       }
     }
 
-    bool IsOrdered = State.VF.isVector() &&
-                     Cost->isInLoopReduction(cast<PHINode>(PN)) &&
+    bool IsOrdered = State.VF.isVector() && IsInLoopReduction &&
                      useOrderedReductions(*RdxDesc);
 
     for (unsigned Part = 0; Part < State.UF; ++Part) {
@@ -9174,16 +9168,32 @@
 
   // Finally, if tail is folded by masking, introduce selects between the phi
   // and the live-out instruction of each reduction, at the end of the latch.
-  if (CM.foldTailByMasking() && !Legal->getReductionVars().empty()) {
-    Builder.setInsertPoint(VPBB);
-    auto *Cond = RecipeBuilder.createBlockInMask(OrigLoop->getHeader(), Plan);
-    for (auto &Reduction : Legal->getReductionVars()) {
-      if (CM.isInLoopReduction(Reduction.first))
+  if (CM.foldTailByMasking()) {
+    VPValue *Cond = nullptr;
+    unsigned NumRegularReductions = 0;
+    for (VPRecipeBase &R : Plan->getEntry()->getEntryBasicBlock()->phis()) {
+      VPWidenPHIRecipe *PhiR = dyn_cast<VPWidenPHIRecipe>(&R);
+      if (!PhiR || !PhiR->getRecurrenceDescriptor() ||
+          PhiR->isInLoopReduction())
         continue;
-      VPValue *Phi = Plan->getOrAddVPValue(Reduction.first);
-      VPValue *Red = Plan->getOrAddVPValue(Reduction.second.getLoopExitInstr());
+
+      if (!Cond) {
+        Builder.setInsertPoint(VPBB);
+        Cond = RecipeBuilder.createBlockInMask(OrigLoop->getHeader(), Plan);
+      }
+      VPValue *Phi = PhiR;
+      VPValue *Red = Plan->getOrAddVPValue(
+          PhiR->getRecurrenceDescriptor()->getLoopExitInstr());
       Builder.createNaryOp(Instruction::Select, {Cond, Red, Phi});
+#ifndef NDEBUG
+      NumRegularReductions++;
+#endif
     }
+    (void)NumRegularReductions;
+    assert(!Range.Start.isVector() ||
+           NumRegularReductions == Legal->getReductionVars().size() -
+                                       CM.getInLoopReductionChains().size() &&
+               "failed to identify an in-loop reduction in VPlan");
   }
 
   std::string PlanName;
diff --git a/llvm/lib/Transforms/Vectorize/VPlan.h b/llvm/lib/Transforms/Vectorize/VPlan.h
--- a/llvm/lib/Transforms/Vectorize/VPlan.h
+++ b/llvm/lib/Transforms/Vectorize/VPlan.h
@@ -1048,6 +1048,12 @@
     return getOperand(1);
   }
 
+  const VPValue *getBackedgeValue() const {
+    assert(RdxDesc && "second incoming value is only guaranteed to be backedge "
+                      "value for reductions");
+    return getOperand(1);
+  }
+
   /// Adds a pair (\p IncomingV, \p IncomingBlock) to the phi.
   void addIncoming(VPValue *IncomingV, VPBasicBlock *IncomingBlock) {
     addOperand(IncomingV);
@@ -1061,6 +1067,9 @@
   VPBasicBlock *getIncomingBlock(unsigned I) { return IncomingBlocks[I]; }
 
   RecurrenceDescriptor *getRecurrenceDescriptor() { return RdxDesc; }
+
+  /// Returns true if this phi is part of an in-loop reduction.
+  bool isInLoopReduction() const;
 };
 
 /// A recipe for vectorizing a phi-node as a sequence of mask-based select
diff --git a/llvm/lib/Transforms/Vectorize/VPlan.cpp b/llvm/lib/Transforms/Vectorize/VPlan.cpp
--- a/llvm/lib/Transforms/Vectorize/VPlan.cpp
+++ b/llvm/lib/Transforms/Vectorize/VPlan.cpp
@@ -1073,6 +1073,30 @@
   printOperands(O, SlotTracker);
 }
 
+bool VPWidenPHIRecipe::isInLoopReduction() const {
+  if (!RdxDesc)
+    return false;
+
+  SmallVector<const VPRecipeBase *, 4> WorkList;
+  // Walk backwards the backedge value until we either reach a VPReductionRecipe
+  // or a phi.
+  WorkList.push_back(cast<VPRecipeBase>(getBackedgeValue()->getDef()));
+  while (!WorkList.empty()) {
+    const VPRecipeBase *Current = WorkList.pop_back_val();
+    if (Current->isPhi())
+      continue;
+    if (isa<VPReductionRecipe>(Current))
+      return true;
+    for (VPValue *Op : Current->operands()) {
+      if (!Op->getDef())
+        continue;
+      if (auto *R = dyn_cast<VPRecipeBase>(Op->getDef()))
+        WorkList.push_back(R);
+    }
+  }
+  return false;
+}
+
 void VPBlendRecipe::print(raw_ostream &O, const Twine &Indent,
                           VPSlotTracker &SlotTracker) const {
   O << Indent << "BLEND ";
diff --git a/llvm/lib/Transforms/Vectorize/VPlanValue.h b/llvm/lib/Transforms/Vectorize/VPlanValue.h
--- a/llvm/lib/Transforms/Vectorize/VPlanValue.h
+++ b/llvm/lib/Transforms/Vectorize/VPlanValue.h
@@ -172,6 +172,7 @@
   void replaceAllUsesWith(VPValue *New);
 
   VPDef *getDef() { return Def; }
+  const VPDef *getDef() const { return Def; }
 
   /// Returns the underlying IR value, if this VPValue is defined outside the
   /// scope of VPlan. Returns nullptr if the VPValue is defined by a VPDef