Index: lib/Transforms/Vectorize/VPlan.h
===================================================================
--- lib/Transforms/Vectorize/VPlan.h
+++ lib/Transforms/Vectorize/VPlan.h
@@ -556,6 +556,10 @@
   /// Unlink this recipe from its current VPBasicBlock and insert it into
   /// the VPBasicBlock that MovePos lives in, right after MovePos.
   void moveAfter(VPRecipeBase *MovePos);
+
+  /// Insert an unlinked instruction into a basic block immediately before
+  /// the specified instruction.
+  void insertBefore(VPRecipeBase *InsertPos);
 };
 
 /// This is a concrete Recipe that models a single VPlan-level instruction.
Index: lib/Transforms/Vectorize/VPlan.cpp
===================================================================
--- lib/Transforms/Vectorize/VPlan.cpp
+++ lib/Transforms/Vectorize/VPlan.cpp
@@ -226,6 +226,11 @@
       getIterator());
 }
 
+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/Vectorize/VPlanTest.cpp
===================================================================
--- unittests/Transforms/Vectorize/VPlanTest.cpp
+++ unittests/Transforms/Vectorize/VPlanTest.cpp
@@ -51,6 +51,21 @@
   CHECK_ITERATOR(VPBB2, I4, I3, I5);
 }
 
+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);
+}
+
 TEST(VPInstructionTest, sinkInstructions) {
   // Create some dummy instructions, we need those for the SinkAfter mapping.
   LLVMContext Context;