Index: include/llvm/IR/LLVMContext.h
===================================================================
--- include/llvm/IR/LLVMContext.h
+++ include/llvm/IR/LLVMContext.h
@@ -62,7 +62,8 @@
     MD_dereferenceable = 12, // "dereferenceable"
     MD_dereferenceable_or_null = 13, // "dereferenceable_or_null"
     MD_make_implicit = 14, // "make.implicit"
-    MD_unpredictable = 15 // "unpredictable"
+    MD_unpredictable = 15, // "unpredictable"
+    MD_invariant_group = 16 // "invariant.group"
   };
 
   /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
Index: lib/CodeGen/CodeGenPrepare.cpp
===================================================================
--- lib/CodeGen/CodeGenPrepare.cpp
+++ lib/CodeGen/CodeGenPrepare.cpp
@@ -4836,6 +4836,6 @@
 }
 
 void CodeGenPrepare::stripInvariantGroupMetadata(Instruction &I) {
-  if (auto *InvariantMD = I.getMetadata("invariant.group"))
+  if (auto *InvariantMD = I.getMetadata(LLVMContext::MD_invariant_group))
     I.dropUnknownNonDebugMetadata(InvariantMD->getMetadataID());
 }
Index: lib/IR/LLVMContext.cpp
===================================================================
--- lib/IR/LLVMContext.cpp
+++ lib/IR/LLVMContext.cpp
@@ -116,6 +116,13 @@
   assert(UnpredictableID == MD_unpredictable &&
          "unpredictable kind id drifted");
   (void)UnpredictableID;
+
+  // Create the 'invariant.group' metadata kind.
+  unsigned InvariantGroupId = getMDKindID("invariant.group");
+  assert(InvariantGroupId == MD_invariant_group &&
+         "invariant.group kind id drifted");
+  (void)InvariantGroupId;
+
 }
 LLVMContext::~LLVMContext() { delete pImpl; }