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
@@ -735,6 +735,14 @@
     return Opcode == Instruction::Store || Opcode == Instruction::Call ||
            Opcode == Instruction::Invoke || Opcode == SLPStore;
   }
+
+  bool hasResult() const {
+    if (const Value *UV = getUnderlyingValue())
+      return !UV->getType()->isVoidTy();
+    // Conservatively assume all VPInstructions without underlying values
+    // produce results.
+    return true;
+  }
 };
 
 /// VPWidenRecipe is a recipe for producing a copy of vector type for each
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
@@ -405,7 +405,8 @@
 
 void VPInstruction::print(raw_ostream &O, VPSlotTracker &SlotTracker) const {
   printAsOperand(O, SlotTracker);
-  O << " = ";
+  if (hasResult())
+    O << " = ";
 
   switch (getOpcode()) {
   case VPInstruction::Not:
@@ -814,11 +815,29 @@
 }
 
 void VPValue::printAsOperand(raw_ostream &OS, VPSlotTracker &Tracker) const {
+  if (const Value *UV = getUnderlyingValue()) {
+    if (UV->getType()->isVoidTy())
+      return;
+    // Get a string of underlying value from printAsOperand, so we can also handle numbered IR values without a name.
+    std::string UnderlyingName;
+    {
+      raw_string_ostream StrStream(UnderlyingName);
+      UV->printAsOperand(StrStream, false);
+      StrStream.flush();
+    }
+    if (isa<Constant>(UV))
+      OS << "ir constant " << UnderlyingName;
+    else
+      // Drop the % from the name.
+      OS << "%vp.ir." << StringRef(UnderlyingName).drop_front(1);
+    return;
+  }
+
   unsigned Slot = Tracker.getSlot(this);
   if (Slot == unsigned(-1))
     OS << "<badref>";
   else
-    OS << "%vp" << Tracker.getSlot(this);
+    OS << "%vp." << Tracker.getSlot(this);
 }
 
 void VPInterleavedAccessInfo::visitRegion(VPRegionBlock *Region,
@@ -869,7 +888,9 @@
 
 void VPSlotTracker::assignSlot(const VPValue *V) {
   assert(Slots.find(V) == Slots.end() && "VPValue already has a slot!");
-  Slots[V] = NextSlot++;
+  const Value *UV = V->getUnderlyingValue();
+  if (!UV || !UV->hasName())
+    Slots[V] = NextSlot++;
 }
 
 void VPSlotTracker::assignSlots(const VPBlockBase *VPBB) {
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
@@ -42,6 +42,7 @@
   friend class VPlanTransforms;
   friend class VPBasicBlock;
   friend class VPInterleavedAccessInfo;
+  friend class VPSlotTracker;
 
 private:
   const unsigned char SubclassID; ///< Subclass identifier (for isa/dyn_cast).
@@ -64,6 +65,7 @@
 
   /// Return the underlying Value attached to this VPValue.
   Value *getUnderlyingValue() { return UnderlyingVal; }
+  const Value *getUnderlyingValue() const { return UnderlyingVal; }
 
   // Set \p Val as the underlying Value of this VPValue.
   void setUnderlyingValue(Value *Val) {
diff --git a/llvm/unittests/Transforms/Vectorize/VPlanHCFGTest.cpp b/llvm/unittests/Transforms/Vectorize/VPlanHCFGTest.cpp
--- a/llvm/unittests/Transforms/Vectorize/VPlanHCFGTest.cpp
+++ b/llvm/unittests/Transforms/Vectorize/VPlanHCFGTest.cpp
@@ -10,6 +10,7 @@
 #include "../lib/Transforms/Vectorize/VPlanTransforms.h"
 #include "VPlanTestBase.h"
 #include "gtest/gtest.h"
+#include <string>
 
 namespace llvm {
 namespace {
@@ -88,6 +89,42 @@
   EXPECT_EQ(IndvarAdd, ICmp->getOperand(0));
   EXPECT_EQ(VecBB->getCondBit(), ICmp);
 
+  std::string FullDump;
+  raw_string_ostream(FullDump) << *Plan;
+  EXPECT_EQ(R"(digraph VPlan {
+graph [labelloc=t, fontsize=30; label="Vectorization Plan"]
+node [shape=rect, fontname=Courier, fontsize=30]
+edge [fontname=Courier, fontsize=30]
+compound=true
+  subgraph cluster_N0 {
+    fontname=Courier
+    label="\<x1\> TopRegion"
+    N1 [label =
+      "entry:\n"
+    ]
+    N1 -> N2 [ label=""]
+    N2 [label =
+      "for.body:\n" +
+        "EMIT %vp.ir.indvars.iv = phi ir constant 0 %vp.ir.indvars.iv.next\l" +
+        "EMIT %vp.ir.arr.idx = getelementptr %vp.ir.A %vp.ir.indvars.iv\l" +
+        "EMIT %vp.ir.l1 = load %vp.ir.arr.idx\l" +
+        "EMIT %vp.ir.res = add %vp.ir.l1 ir constant 10\l" +
+        "EMIT store %vp.ir.res %vp.ir.arr.idx\l" +
+        "EMIT %vp.ir.indvars.iv.next = add %vp.ir.indvars.iv ir constant 1\l" +
+        "EMIT %vp.ir.exitcond = icmp %vp.ir.indvars.iv.next %vp.ir.N\l" +
+         "CondBit: %vp.ir.exitcond (for.body)\l"
+    ]
+    N2 -> N2 [ label="T"]
+    N2 -> N3 [ label="F"]
+    N3 [label =
+      "for.end:\n" +
+        "EMIT ret\l"
+    ]
+  }
+}
+)",
+            FullDump);
+
   LoopVectorizationLegality::InductionList Inductions;
   SmallPtrSet<Instruction *, 1> DeadInstructions;
   VPlanTransforms::VPInstructionsToVPRecipes(LI->getLoopFor(LoopHeader), Plan,
diff --git a/llvm/unittests/Transforms/Vectorize/VPlanTest.cpp b/llvm/unittests/Transforms/Vectorize/VPlanTest.cpp
--- a/llvm/unittests/Transforms/Vectorize/VPlanTest.cpp
+++ b/llvm/unittests/Transforms/Vectorize/VPlanTest.cpp
@@ -216,15 +216,15 @@
 compound=true
   N0 [label =
     ":\n" +
-      "EMIT %vp0 = catchswitch\l" +
-      "EMIT %vp1 = ret %vp0\l" +
-      "EMIT %vp2 = br %vp0 %vp1\l"
+      "EMIT %vp.0 = catchswitch\l" +
+      "EMIT %vp.1 = ret %vp.0\l" +
+      "EMIT %vp.2 = br %vp.0 %vp.1\l"
   ]
   N0 -> N1 [ label=""]
   N1 [label =
     ":\n" +
-      "EMIT %vp3 = indirectbr %vp2 %vp1\l" +
-      "EMIT %vp4 = invoke %vp0\l"
+      "EMIT %vp.3 = indirectbr %vp.2 %vp.1\l" +
+      "EMIT %vp.4 = invoke %vp.0\l"
   ]
 }
 )",
@@ -235,7 +235,7 @@
     raw_string_ostream OS(I3Dump);
     I3->print(OS);
     OS.flush();
-    EXPECT_EQ("%vp2 = br %vp0 %vp1", I3Dump);
+    EXPECT_EQ("%vp.2 = br %vp.0 %vp.1", I3Dump);
   }
 
   {
@@ -243,7 +243,7 @@
     raw_string_ostream OS(I2Dump);
     OS << *I2;
     OS.flush();
-    EXPECT_EQ("%vp1 = ret %vp0", I2Dump);
+    EXPECT_EQ("%vp.1 = ret %vp.0", I2Dump);
   }
 }