Index: llvm/include/llvm/Transforms/Utils/SampleProfileLoaderBaseUtil.h
===================================================================
--- llvm/include/llvm/Transforms/Utils/SampleProfileLoaderBaseUtil.h
+++ llvm/include/llvm/Transforms/Utils/SampleProfileLoaderBaseUtil.h
@@ -19,10 +19,12 @@
 #include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/CFG.h"
+#include "llvm/IR/Constants.h"
 #include "llvm/IR/DebugLoc.h"
 #include "llvm/IR/Function.h"
 #include "llvm/ProfileData/SampleProf.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Transforms/Utils/ModuleUtils.h"
 
 namespace llvm {
 using namespace sampleprof;
@@ -92,6 +94,10 @@
 /// Return true if the given callsite is hot wrt to hot cutoff threshold.
 bool callsiteIsHot(const FunctionSamples *CallsiteFS, ProfileSummaryInfo *PSI,
                    bool ProfAccForSymsInList);
+
+/// Create a global variable to flag that FSDiscriminators are used.
+void createFSDiscriminatorVariable(Module *M);
+
 } // end of namespace sampleprofutil
 } // end of namespace llvm
 
Index: llvm/lib/CodeGen/MIRFSDiscriminator.cpp
===================================================================
--- llvm/lib/CodeGen/MIRFSDiscriminator.cpp
+++ llvm/lib/CodeGen/MIRFSDiscriminator.cpp
@@ -19,10 +19,12 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Utils/SampleProfileLoaderBaseUtil.h"
 #include <unordered_map>
 
 using namespace llvm;
 using namespace sampleprof;
+using namespace sampleprofutil;
 
 #define DEBUG_TYPE "mirfs-discriminators"
 
@@ -127,16 +129,7 @@
   }
 
   if (Changed) {
-    Module *M = MF.getFunction().getParent();
-    const char *FSDiscriminatorVar = "__llvm_fs_discriminator__";
-    if (!M->getGlobalVariable(FSDiscriminatorVar)) {
-      auto &Context = M->getContext();
-      // Create a global variable to flag that FSDiscriminators are used.
-      new GlobalVariable(*M, Type::getInt1Ty(Context), true,
-                         GlobalValue::WeakAnyLinkage,
-                         ConstantInt::getTrue(Context), FSDiscriminatorVar);
-    }
-
+    createFSDiscriminatorVariable(MF.getFunction().getParent());
     LLVM_DEBUG(dbgs() << "Num of FS Discriminators: " << NumNewD << "\n");
   }
 
Index: llvm/lib/Transforms/Utils/AddDiscriminators.cpp
===================================================================
--- llvm/lib/Transforms/Utils/AddDiscriminators.cpp
+++ llvm/lib/Transforms/Utils/AddDiscriminators.cpp
@@ -70,9 +70,11 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Utils.h"
+#include "llvm/Transforms/Utils/SampleProfileLoaderBaseUtil.h"
 #include <utility>
 
 using namespace llvm;
+using namespace sampleprofutil;
 
 #define DEBUG_TYPE "add-discriminators"
 
@@ -172,6 +174,10 @@
   if (NoDiscriminators || !F.getSubprogram())
     return false;
 
+  // Create FSDiscriminatorVariable if flow sensitive discriminators are used.
+  if (EnableFSDiscriminator)
+    createFSDiscriminatorVariable(F.getParent());
+
   bool Changed = false;
 
   using Location = std::pair<StringRef, unsigned>;
Index: llvm/lib/Transforms/Utils/SampleProfileLoaderBaseUtil.cpp
===================================================================
--- llvm/lib/Transforms/Utils/SampleProfileLoaderBaseUtil.cpp
+++ llvm/lib/Transforms/Utils/SampleProfileLoaderBaseUtil.cpp
@@ -159,5 +159,19 @@
   return Total > 0 ? Used * 100 / Total : 100;
 }
 
+/// Create a global variable to flag that FSDiscriminators are used.
+void createFSDiscriminatorVariable(Module *M) {
+  const char *FSDiscriminatorVar = "__llvm_fs_discriminator__";
+  if (M->getGlobalVariable(FSDiscriminatorVar))
+    return;
+
+  auto &Context = M->getContext();
+  // Place this variable to llvm.used so it won't be GC'ed.
+  appendToUsed(*M, {new GlobalVariable(*M, Type::getInt1Ty(Context), true,
+                                       GlobalValue::WeakODRLinkage,
+                                       ConstantInt::getTrue(Context),
+                                       FSDiscriminatorVar)});
+}
+
 } // end of namespace sampleprofutil
 } // end of namespace llvm