diff --git a/include/llvm/MC/MCDirectives.h b/include/llvm/MC/MCDirectives.h
index 982f25a..e4e023d 100644
--- a/include/llvm/MC/MCDirectives.h
+++ b/include/llvm/MC/MCDirectives.h
@@ -44,7 +44,8 @@
 
 enum MCAssemblerFlag {
   MCAF_SyntaxUnified,         ///< .syntax (ARM/ELF)
-  MCAF_SubsectionsViaSymbols  ///< .subsections_via_symbols (MachO)
+  MCAF_SubsectionsViaSymbols, ///< .subsections_via_symbols (MachO)
+  MCAF_Code16                 ///< .code 16
 };
 
 } // end namespace llvm
diff --git a/include/llvm/MC/MCStreamer.h b/include/llvm/MC/MCStreamer.h
index fd6e690..089650c 100644
--- a/include/llvm/MC/MCStreamer.h
+++ b/include/llvm/MC/MCStreamer.h
@@ -126,6 +126,10 @@
     /// EmitAssemblerFlag - Note in the output the specified @p Flag
     virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0;
 
+    /// EmitThumbFunc - Note in the output that the specified @p Func is
+    /// a Thumb mode function (ARM target only).
+    virtual void EmitThumbFunc(MCSymbol *Func) = 0;
+
     /// EmitAssignment - Emit an assignment of @p Value to @p Symbol.
     ///
     /// This corresponds to an assembler statement such as:
diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index 54f0163..5dd115d 100644
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -111,6 +111,7 @@
   virtual void EmitLabel(MCSymbol *Symbol);
 
   virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
+  virtual void EmitThumbFunc(MCSymbol *Func);
 
   virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
   virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol);
@@ -253,10 +254,20 @@
   default: assert(0 && "Invalid flag!");
   case MCAF_SyntaxUnified:         OS << "\t.syntax unified"; break;
   case MCAF_SubsectionsViaSymbols: OS << ".subsections_via_symbols"; break;
+  case MCAF_Code16:                OS << "\t.code\t16"; break;
   }
   EmitEOL();
 }
 
+void MCAsmStreamer::EmitThumbFunc(MCSymbol *Func) {
+  // This needs to emit to a temporary string to get properly quoted
+  // MCSymbols when they have spaces in them.
+  OS << "\t.thumb_func";
+  if (Func)
+    OS << '\t' << *Func;
+  EmitEOL();
+}
+
 void MCAsmStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
   OS << *Symbol << " = " << *Value;
   EmitEOL();
diff --git a/lib/MC/MCELFStreamer.cpp b/lib/MC/MCELFStreamer.cpp
index 2a12fa2..da7257f 100644
--- a/lib/MC/MCELFStreamer.cpp
+++ b/lib/MC/MCELFStreamer.cpp
@@ -49,6 +49,7 @@
   virtual void InitSections();
   virtual void EmitLabel(MCSymbol *Symbol);
   virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
+  virtual void EmitThumbFunc(MCSymbol *Func);
   virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
   virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol);
   virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
@@ -178,7 +179,8 @@
 
 void MCELFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
   switch (Flag) {
-  case MCAF_SyntaxUnified:  return; // no-op here?
+  case MCAF_SyntaxUnified: return; // no-op here.
+  case MCAF_Code16: return; // no-op here.
   case MCAF_SubsectionsViaSymbols:
     getAssembler().setSubsectionsViaSymbols(true);
     return;
@@ -187,6 +189,10 @@
   assert(0 && "invalid assembler flag!");
 }
 
+void MCELFStreamer::EmitThumbFunc(MCSymbol *Func) {
+  // FIXME: Anything needed here to flag the function as thumb?
+}
+
 void MCELFStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
   // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
   // MCObjectStreamer.
diff --git a/lib/MC/MCLoggingStreamer.cpp b/lib/MC/MCLoggingStreamer.cpp
index cb217c7..9681c06 100644
--- a/lib/MC/MCLoggingStreamer.cpp
+++ b/lib/MC/MCLoggingStreamer.cpp
@@ -69,6 +69,11 @@
     return Child->EmitAssemblerFlag(Flag);
   }
 
+  virtual void EmitThumbFunc(MCSymbol *Func) {
+    LogCall("EmitThumbFunc");
+    return Child->EmitThumbFunc(Func);
+  }
+
   virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
     LogCall("EmitAssignment");
     return Child->EmitAssignment(Symbol, Value);
diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp
index 6690618..b652198 100644
--- a/lib/MC/MCMachOStreamer.cpp
+++ b/lib/MC/MCMachOStreamer.cpp
@@ -45,6 +45,7 @@
   virtual void InitSections();
   virtual void EmitLabel(MCSymbol *Symbol);
   virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
+  virtual void EmitThumbFunc(MCSymbol *Func);
   virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
   virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
   virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
@@ -149,7 +150,8 @@
 
 void MCMachOStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
   switch (Flag) {
-  case MCAF_SyntaxUnified:  return; // no-op here.
+  case MCAF_SyntaxUnified: return; // no-op here.
+  case MCAF_Code16: return; // no-op here.
   case MCAF_SubsectionsViaSymbols:
     getAssembler().setSubsectionsViaSymbols(true);
     return;
@@ -158,6 +160,10 @@
   }
 }
 
+void MCMachOStreamer::EmitThumbFunc(MCSymbol *Func) {
+  // FIXME: Flag the function ISA as thumb with DW_AT_APPLE_isa.
+}
+
 void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
   // TODO: This is exactly the same as WinCOFFStreamer. Consider merging into
   // MCObjectStreamer.
diff --git a/lib/MC/MCNullStreamer.cpp b/lib/MC/MCNullStreamer.cpp
index 9dfb28c..b95a4f6 100644
--- a/lib/MC/MCNullStreamer.cpp
+++ b/lib/MC/MCNullStreamer.cpp
@@ -40,6 +40,7 @@
     }
 
     virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {}
+    virtual void EmitThumbFunc(MCSymbol *Func) {}
 
     virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {}
     virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol){}
diff --git a/lib/MC/WinCOFFStreamer.cpp b/lib/MC/WinCOFFStreamer.cpp
index 5a2a7f9..3c5a3be 100644
--- a/lib/MC/WinCOFFStreamer.cpp
+++ b/lib/MC/WinCOFFStreamer.cpp
@@ -51,6 +51,7 @@
   virtual void InitSections();
   virtual void EmitLabel(MCSymbol *Symbol);
   virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
+  virtual void EmitThumbFunc(MCSymbol *Func);
   virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
   virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
   virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
@@ -202,6 +203,10 @@
   llvm_unreachable("not implemented");
 }
 
+void WinCOFFStreamer::EmitThumbFunc(MCSymbol *Func) {
+  llvm_unreachable("not implemented");
+}
+
 void WinCOFFStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
   assert((Symbol->isInSection()
          ? Symbol->getSection().getVariant() == MCSection::SV_COFF
diff --git a/lib/Target/ARM/ARMAsmPrinter.cpp b/lib/Target/ARM/ARMAsmPrinter.cpp
index 9327bb7..3908b1e 100644
--- a/lib/Target/ARM/ARMAsmPrinter.cpp
+++ b/lib/Target/ARM/ARMAsmPrinter.cpp
@@ -299,17 +299,8 @@
 
 void ARMAsmPrinter::EmitFunctionEntryLabel() {
   if (AFI->isThumbFunction()) {
-    OutStreamer.EmitRawText(StringRef("\t.code\t16"));
-    if (!Subtarget->isTargetDarwin())
-      OutStreamer.EmitRawText(StringRef("\t.thumb_func"));
-    else {
-      // This needs to emit to a temporary string to get properly quoted
-      // MCSymbols when they have spaces in them.
-      SmallString<128> Tmp;
-      raw_svector_ostream OS(Tmp);
-      OS << "\t.thumb_func\t" << *CurrentFnSym;
-      OutStreamer.EmitRawText(OS.str());
-    }
+    OutStreamer.EmitAssemblerFlag(MCAF_Code16);
+    OutStreamer.EmitThumbFunc(Subtarget->isTargetDarwin()? CurrentFnSym : 0);
   }
 
   OutStreamer.EmitLabel(CurrentFnSym);