Index: lib/Transforms/Vectorize/VPlan.h
===================================================================
--- lib/Transforms/Vectorize/VPlan.h
+++ lib/Transforms/Vectorize/VPlan.h
@@ -552,6 +552,10 @@
 
   /// Each recipe prints itself.
   virtual void print(raw_ostream &O, const Twine &Indent) const = 0;
+
+  /// Insert an unlinked recipe into a basic block immediately before
+  /// the specified recipe.
+  void insertBefore(VPRecipeBase *InsertPos);
 };
 
 /// This is a concrete Recipe that models a single VPlan-level instruction.
@@ -923,6 +927,9 @@
   inline const VPRecipeBase &back() const { return Recipes.back(); }
   inline VPRecipeBase &back() { return Recipes.back(); }
 
+  /// Returns a reference to the list of recipes.
+  RecipeListTy &getRecipeList() { return Recipes; }
+
   /// Returns a pointer to a member of the recipe list.
   static RecipeListTy VPBasicBlock::*getSublistAccess(VPRecipeBase *) {
     return &VPBasicBlock::Recipes;
Index: lib/Transforms/Vectorize/VPlan.cpp
===================================================================
--- lib/Transforms/Vectorize/VPlan.cpp
+++ lib/Transforms/Vectorize/VPlan.cpp
@@ -220,6 +220,11 @@
   State->Instance.reset();
 }
 
+void VPRecipeBase::insertBefore(VPRecipeBase *InsertPos) {
+  InsertPos->getParent()->getRecipeList().insert(InsertPos->getIterator(),
+                                                 this);
+}
+
 void VPInstruction::generateInstruction(VPTransformState &State,
                                         unsigned Part) {
   IRBuilder<> &Builder = State.Builder;
Index: unittests/Transforms/CMakeLists.txt
===================================================================
--- unittests/Transforms/CMakeLists.txt
+++ unittests/Transforms/CMakeLists.txt
@@ -1,3 +1,4 @@
 add_subdirectory(IPO)
 add_subdirectory(Scalar)
 add_subdirectory(Utils)
+add_subdirectory(Vectorize)
Index: unittests/Transforms/Vectorize/CMakeLists.txt
===================================================================
--- /dev/null
+++ unittests/Transforms/Vectorize/CMakeLists.txt
@@ -0,0 +1,7 @@
+set(LLVM_LINK_COMPONENTS
+  Vectorize
+  )
+
+add_llvm_unittest(VectorizeTests
+  VPlanTest.cpp
+  )
Index: unittests/Transforms/Vectorize/VPlanTest.cpp
===================================================================
--- /dev/null
+++ unittests/Transforms/Vectorize/VPlanTest.cpp
@@ -0,0 +1,44 @@
+//===- llvm/unittests/Transforms/Vectorize/VPlanTest.cpp - VPlan tests ----===//
+//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "../lib/Transforms/Vectorize/VPlan.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/Instructions.h"
+#include "gtest/gtest.h"
+
+namespace llvm {
+namespace {
+
+#define CHECK_ITERATOR(Range1, ...)                                            \
+  do {                                                                         \
+    std::vector<VPInstruction *> Tmp = {__VA_ARGS__};                          \
+    EXPECT_EQ((size_t)std::distance(Range1.begin(), Range1.end()),             \
+              Tmp.size());                                                     \
+    for (auto Pair : zip(Range1, make_range(Tmp.begin(), Tmp.end())))          \
+      EXPECT_EQ(&std::get<0>(Pair), std::get<1>(Pair));                        \
+  } while (0)
+
+TEST(VPInstructionTest, insertBefore) {
+  VPInstruction *I1 = new VPInstruction(0, {});
+  VPInstruction *I2 = new VPInstruction(1, {});
+  VPInstruction *I3 = new VPInstruction(2, {});
+
+  VPBasicBlock VPBB1;
+  VPBB1.appendRecipe(I1);
+
+  I2->insertBefore(I1);
+  CHECK_ITERATOR(VPBB1, I2, I1);
+
+  I3->insertBefore(I2);
+  CHECK_ITERATOR(VPBB1, I3, I2, I1);
+}
+
+} // namespace
+} // namespace llvm