Index: lib/Target/ARM/ARM.h
===================================================================
--- lib/Target/ARM/ARM.h
+++ lib/Target/ARM/ARM.h
@@ -61,6 +61,7 @@
 void initializeARMPreAllocLoadStoreOptPass(PassRegistry &);
 void initializeARMConstantIslandsPass(PassRegistry &);
 void initializeARMExpandPseudoPass(PassRegistry &);
+void initializeThumb2SizeReducePass(PassRegistry &);
 
 } // end namespace llvm
 
Index: lib/Target/ARM/ARMTargetMachine.cpp
===================================================================
--- lib/Target/ARM/ARMTargetMachine.cpp
+++ lib/Target/ARM/ARMTargetMachine.cpp
@@ -92,6 +92,7 @@
   initializeARMConstantIslandsPass(Registry);
   initializeARMExecutionDepsFixPass(Registry);
   initializeARMExpandPseudoPass(Registry);
+  initializeThumb2SizeReducePass(Registry);
 }
 
 static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
Index: lib/Target/ARM/Thumb2SizeReduction.cpp
===================================================================
--- lib/Target/ARM/Thumb2SizeReduction.cpp
+++ lib/Target/ARM/Thumb2SizeReduction.cpp
@@ -45,6 +45,7 @@
 using namespace llvm;
 
 #define DEBUG_TYPE "t2-reduce-size"
+#define THUMB2_SIZE_REDUCE_NAME "Thumb2 instruction size reduce pass"
 
 STATISTIC(NumNarrows,  "Number of 32-bit instrs reduced to 16-bit ones");
 STATISTIC(Num2Addrs,   "Number of 32-bit instrs reduced to 2addr 16-bit ones");
@@ -162,7 +163,7 @@
     const Thumb2InstrInfo *TII;
     const ARMSubtarget *STI;
 
-    Thumb2SizeReduce(std::function<bool(const Function &)> Ftor);
+    Thumb2SizeReduce(std::function<bool(const Function &)> Ftor = nullptr);
 
     bool runOnMachineFunction(MachineFunction &MF) override;
 
@@ -172,7 +173,7 @@
     }
 
     StringRef getPassName() const override {
-      return "Thumb2 instruction size reduction pass";
+      return THUMB2_SIZE_REDUCE_NAME;
     }
 
   private:
@@ -237,6 +238,9 @@
 
 } // end anonymous namespace
 
+INITIALIZE_PASS(Thumb2SizeReduce, DEBUG_TYPE, THUMB2_SIZE_REDUCE_NAME, false,
+                false)
+
 Thumb2SizeReduce::Thumb2SizeReduce(std::function<bool(const Function &)> Ftor)
     : MachineFunctionPass(ID), PredicateFtor(std::move(Ftor)) {
   OptimizeSize = MinimizeSize = false;