diff --git a/include/llvm/CodeGen/MachineFunction.h b/include/llvm/CodeGen/MachineFunction.h
index c6bcca7f7b3..4ffd4bdc2f3 100644
--- a/include/llvm/CodeGen/MachineFunction.h
+++ b/include/llvm/CodeGen/MachineFunction.h
@@ -223,7 +223,7 @@ struct LandingPadInfo {
 };
 
 class MachineFunction {
-  const Function *Fn;
+  const Function &F;
   const TargetMachine &Target;
   const TargetSubtargetInfo *STI;
   MCContext &Ctx;
@@ -359,8 +359,9 @@ public:
   using VariableDbgInfoMapTy = SmallVector<VariableDbgInfo, 4>;
   VariableDbgInfoMapTy VariableDbgInfos;
 
-  MachineFunction(const Function *Fn, const TargetMachine &TM,
-                  unsigned FunctionNum, MachineModuleInfo &MMI);
+  MachineFunction(const Function &F, const TargetMachine &TM,
+                  const TargetSubtargetInfo &STI, unsigned FunctionNum,
+                  MachineModuleInfo &MMI);
   MachineFunction(const MachineFunction &) = delete;
   MachineFunction &operator=(const MachineFunction &) = delete;
   ~MachineFunction();
@@ -380,7 +381,7 @@ public:
   const DataLayout &getDataLayout() const;
 
   /// getFunction - Return the LLVM function that this machine code represents
-  const Function *getFunction() const { return Fn; }
+  const Function *getFunction() const { return &F; }
 
   /// getName - Return the name of the corresponding LLVM function.
   StringRef getName() const;
diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
index dba0dfbe886..5ffc8914b96 100644
--- a/lib/CodeGen/MachineFunction.cpp
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -119,16 +119,16 @@ void ilist_alloc_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
 }
 
 static inline unsigned getFnStackAlignment(const TargetSubtargetInfo *STI,
-                                           const Function *Fn) {
-  if (Fn->hasFnAttribute(Attribute::StackAlignment))
-    return Fn->getFnStackAlignment();
+                                           const Function &F) {
+  if (F.hasFnAttribute(Attribute::StackAlignment))
+    return F.getFnStackAlignment();
   return STI->getFrameLowering()->getStackAlignment();
 }
 
-MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM,
+MachineFunction::MachineFunction(const Function &F, const TargetMachine &Target,
+                                 const TargetSubtargetInfo &STI,
                                  unsigned FunctionNum, MachineModuleInfo &mmi)
-    : Fn(F), Target(TM), STI(TM.getSubtargetImpl(*F)), Ctx(mmi.getContext()),
-      MMI(mmi) {
+    : F(F), Target(Target), STI(&STI), Ctx(mmi.getContext()), MMI(mmi) {
   FunctionNumber = FunctionNum;
   init();
 }
@@ -146,21 +146,21 @@ void MachineFunction::init() {
   // We can realign the stack if the target supports it and the user hasn't
   // explicitly asked us not to.
   bool CanRealignSP = STI->getFrameLowering()->isStackRealignable() &&
-                      !Fn->hasFnAttribute("no-realign-stack");
+                      !F.hasFnAttribute("no-realign-stack");
   FrameInfo = new (Allocator) MachineFrameInfo(
-      getFnStackAlignment(STI, Fn), /*StackRealignable=*/CanRealignSP,
+      getFnStackAlignment(STI, F), /*StackRealignable=*/CanRealignSP,
       /*ForceRealign=*/CanRealignSP &&
-          Fn->hasFnAttribute(Attribute::StackAlignment));
+          F.hasFnAttribute(Attribute::StackAlignment));
 
-  if (Fn->hasFnAttribute(Attribute::StackAlignment))
-    FrameInfo->ensureMaxAlignment(Fn->getFnStackAlignment());
+  if (F.hasFnAttribute(Attribute::StackAlignment))
+    FrameInfo->ensureMaxAlignment(F.getFnStackAlignment());
 
   ConstantPool = new (Allocator) MachineConstantPool(getDataLayout());
   Alignment = STI->getTargetLowering()->getMinFunctionAlignment();
 
-  // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.
+  // FIXME: Shouldn't use pref alignment if explicit alignment is set on F.
   // FIXME: Use Function::optForSize().
-  if (!Fn->hasFnAttribute(Attribute::OptimizeForSize))
+  if (!F.hasFnAttribute(Attribute::OptimizeForSize))
     Alignment = std::max(Alignment,
                          STI->getTargetLowering()->getPrefFunctionAlignment());
 
@@ -170,7 +170,7 @@ void MachineFunction::init() {
   JumpTableInfo = nullptr;
 
   if (isFuncletEHPersonality(classifyEHPersonality(
-          Fn->hasPersonalityFn() ? Fn->getPersonalityFn() : nullptr))) {
+          F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) {
     WinEHInfo = new (Allocator) WinEHFuncInfo();
   }
 
@@ -228,7 +228,7 @@ void MachineFunction::clear() {
 }
 
 const DataLayout &MachineFunction::getDataLayout() const {
-  return Fn->getParent()->getDataLayout();
+  return F.getParent()->getDataLayout();
 }
 
 /// Get the JumpTableInfo for this function.
diff --git a/lib/CodeGen/MachineModuleInfo.cpp b/lib/CodeGen/MachineModuleInfo.cpp
index 560df08c980..8f0b89657d0 100644
--- a/lib/CodeGen/MachineModuleInfo.cpp
+++ b/lib/CodeGen/MachineModuleInfo.cpp
@@ -276,7 +276,8 @@ MachineModuleInfo::getOrCreateMachineFunction(const Function &F) {
   MachineFunction *MF;
   if (I.second) {
     // No pre-existing machine function, create a new one.
-    MF = new MachineFunction(&F, TM, NextFnNum++, *this);
+    const TargetSubtargetInfo &STI = *TM.getSubtargetImpl(F);
+    MF = new MachineFunction(F, TM, STI, NextFnNum++, *this);
     // Update the set entry.
     I.first->second.reset(MF);
   } else {
diff --git a/unittests/CodeGen/MachineInstrTest.cpp b/unittests/CodeGen/MachineInstrTest.cpp
index fe8e792412f..aca640ebcf3 100644
--- a/unittests/CodeGen/MachineInstrTest.cpp
+++ b/unittests/CodeGen/MachineInstrTest.cpp
@@ -91,8 +91,9 @@ std::unique_ptr<MachineFunction> createMachineFunction() {
   auto TM = createTargetMachine();
   unsigned FunctionNum = 42;
   MachineModuleInfo MMI(TM.get());
+  const TargetSubtargetInfo &STI = *TM->getSubtargetImpl(*F);
 
-  return llvm::make_unique<MachineFunction>(F, *TM, FunctionNum, MMI);
+  return llvm::make_unique<MachineFunction>(*F, *TM, STI, FunctionNum, MMI);
 }
 
 // This test makes sure that MachineInstr::isIdenticalTo handles Defs correctly