diff --git a/llvm/lib/MC/WinCOFFObjectWriter.cpp b/llvm/lib/MC/WinCOFFObjectWriter.cpp
index 0cc5ff5d66d8..8f850c0228f3 100644
--- a/llvm/lib/MC/WinCOFFObjectWriter.cpp
+++ b/llvm/lib/MC/WinCOFFObjectWriter.cpp
@@ -168,13 +168,13 @@ public:
 private:
   MCContext &getContext() const { return OWriter.getContext(); }
   COFFSymbol *createSymbol(StringRef Name);
-  COFFSymbol *GetOrCreateCOFFSymbol(const MCSymbol *Symbol);
+  COFFSymbol *getOrCreateCOFFSymbol(const MCSymbol &Sym);
   COFFSection *createSection(StringRef Name);
 
   void defineSection(MCSectionCOFF const &Sec);
 
   COFFSymbol *getLinkedSymbol(const MCSymbol &Symbol);
-  void defineSymbol(const MCSymbol &Symbol);
+  void defineSymbol(const MCSymbolCOFF &Symbol);
 
   void SetSymbolName(COFFSymbol &S);
   void SetSectionName(COFFSection &S);
@@ -244,10 +244,10 @@ COFFSymbol *WinCOFFWriter::createSymbol(StringRef Name) {
   return Symbols.back().get();
 }
 
-COFFSymbol *WinCOFFWriter::GetOrCreateCOFFSymbol(const MCSymbol *Symbol) {
-  COFFSymbol *&Ret = SymbolMap[Symbol];
+COFFSymbol *WinCOFFWriter::getOrCreateCOFFSymbol(const MCSymbol &Sym) {
+  COFFSymbol *&Ret = SymbolMap[&Sym];
   if (!Ret)
-    Ret = createSymbol(Symbol->getName());
+    Ret = createSymbol(Sym.getName());
   return Ret;
 }
 
@@ -303,7 +303,7 @@ void WinCOFFWriter::defineSection(const MCSectionCOFF &MCSec) {
   // Create a COMDAT symbol if needed.
   if (MCSec.getSelection() != COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE) {
     if (const MCSymbol *S = MCSec.getCOMDATSymbol()) {
-      COFFSymbol *COMDATSymbol = GetOrCreateCOFFSymbol(S);
+      COFFSymbol *COMDATSymbol = getOrCreateCOFFSymbol(*S);
       if (COMDATSymbol->Section)
         report_fatal_error("two sections have the same comdat");
       COMDATSymbol->Section = Section;
@@ -339,7 +339,8 @@ void WinCOFFWriter::defineSection(const MCSectionCOFF &MCSec) {
   }
 }
 
-static uint64_t getSymbolValue(const MCSymbol &Symbol, const MCAssembler &Asm) {
+static uint64_t getSymbolValue(const MCSymbolCOFF &Symbol,
+                               const MCAssembler &Asm) {
   if (Symbol.isCommon() && Symbol.isExternal())
     return Symbol.getCommonSize();
 
@@ -354,21 +355,20 @@ COFFSymbol *WinCOFFWriter::getLinkedSymbol(const MCSymbol &Symbol) {
   if (!Symbol.isVariable())
     return nullptr;
 
-  const MCSymbolRefExpr *SymRef =
-      dyn_cast<MCSymbolRefExpr>(Symbol.getVariableValue());
+  const auto *SymRef = dyn_cast<MCSymbolRefExpr>(Symbol.getVariableValue());
   if (!SymRef)
     return nullptr;
 
-  const MCSymbol &Aliasee = SymRef->getSymbol();
+  auto &Aliasee = static_cast<const MCSymbolCOFF &>(SymRef->getSymbol());
   if (Aliasee.isUndefined() || Aliasee.isExternal())
-    return GetOrCreateCOFFSymbol(&Aliasee);
+    return getOrCreateCOFFSymbol(Aliasee);
   else
     return nullptr;
 }
 
 /// This function takes a symbol data object from the assembler
 /// and creates the associated COFF symbol staging object.
-void WinCOFFWriter::defineSymbol(const MCSymbol &MCSym) {
+void WinCOFFWriter::defineSymbol(const MCSymbolCOFF &MCSym) {
   const MCSymbol *Base = Asm->getBaseSymbol(MCSym);
   COFFSection *Sec = nullptr;
   MCSectionCOFF *MCSec = nullptr;
@@ -380,7 +380,7 @@ void WinCOFFWriter::defineSymbol(const MCSymbol &MCSym) {
   if (Mode == NonDwoOnly && MCSec && isDwoSection(*MCSec))
     return;
 
-  COFFSymbol *Sym = GetOrCreateCOFFSymbol(&MCSym);
+  COFFSymbol *Sym = getOrCreateCOFFSymbol(MCSym);
   COFFSymbol *Local = nullptr;
   if (static_cast<const MCSymbolCOFF &>(MCSym)
           .getWeakExternalCharacteristics()) {
@@ -819,13 +819,14 @@ void WinCOFFWriter::executePostLayoutBinding() {
     defineSection(static_cast<const MCSectionCOFF &>(Section));
   }
 
-  if (Mode != DwoOnly)
-    for (const MCSymbol &Symbol : Asm->symbols())
+  if (Mode != DwoOnly) {
+    for (const MCSymbol &Symbol : Asm->symbols()) {
+      auto &Sym = static_cast<const MCSymbolCOFF &>(Symbol);
       // Define non-temporary or temporary static (private-linkage) symbols
-      if (!Symbol.isTemporary() ||
-          static_cast<const MCSymbolCOFF &>(Symbol).getClass() ==
-              COFF::IMAGE_SYM_CLASS_STATIC)
-        defineSymbol(Symbol);
+      if (!Sym.isTemporary() || Sym.getClass() == COFF::IMAGE_SYM_CLASS_STATIC)
+        defineSymbol(Sym);
+    }
+  }
 
   UseBigObj = Sections.size() > COFF::MaxNumberOfSections16;
   Header.NumberOfSections = Sections.size();
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
index cc1c79b7ef9f..5d5a49aff061 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
@@ -25,6 +25,7 @@
 #include "llvm/MC/MCObjectWriter.h"
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/MC/MCSymbolMachO.h"
 #include "llvm/MC/MCTargetOptions.h"
 #include "llvm/MC/MCValue.h"
 #include "llvm/Support/Debug.h"
@@ -437,13 +438,14 @@ unsigned ARMAsmBackend::adjustFixupValue(const MCAssembler &Asm,
   // Other relocation types don't want this bit though (branches couldn't encode
   // it if it *was* present, and no other relocations exist) and it can
   // interfere with checking valid expressions.
-  bool IsMachO = getContext().getObjectFileType() == MCContext::IsMachO;
-  if (const auto *SA = Target.getAddSym()) {
-    if (IsMachO && Asm.isThumbFunc(SA) && SA->isExternal() &&
-        (Kind == FK_Data_4 || Kind == ARM::fixup_arm_movw_lo16 ||
-         Kind == ARM::fixup_arm_movt_hi16 || Kind == ARM::fixup_t2_movw_lo16 ||
-         Kind == ARM::fixup_t2_movt_hi16))
-      Value |= 1;
+  if (getContext().getObjectFileType() == MCContext::IsMachO) {
+    if (auto *SA = static_cast<const MCSymbolMachO *>(Target.getAddSym())) {
+      if (Asm.isThumbFunc(SA) && SA->isExternal() &&
+          (Kind == FK_Data_4 || Kind == ARM::fixup_arm_movw_lo16 ||
+           Kind == ARM::fixup_arm_movt_hi16 ||
+           Kind == ARM::fixup_t2_movw_lo16 || Kind == ARM::fixup_t2_movt_hi16))
+        Value |= 1;
+    }
   }
 
   switch (Kind) {
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
index 0dabd98a38f4..25fcf8158739 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
@@ -17,6 +17,7 @@
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCMachObjectWriter.h"
 #include "llvm/MC/MCSectionMachO.h"
+#include "llvm/MC/MCSymbolMachO.h"
 #include "llvm/MC/MCValue.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Format.h"
@@ -354,8 +355,7 @@ bool X86MachObjectWriter::recordScatteredRelocation(MachObjectWriter *Writer,
   unsigned Type = MachO::GENERIC_RELOC_VANILLA;
 
   // See <reloc.h>.
-  const MCSymbol *A = Target.getAddSym();
-
+  auto *A = static_cast<const MCSymbolMachO *>(Target.getAddSym());
   if (!A->getFragment()) {
     reportError(Fixup.getLoc(),
                 "symbol '" + A->getName() +