Index: include/llvm/MC/MCTargetAsmParser.h
===================================================================
--- include/llvm/MC/MCTargetAsmParser.h
+++ include/llvm/MC/MCTargetAsmParser.h
@@ -183,6 +183,8 @@
   }
 
   virtual void onLabelParsed(MCSymbol *Symbol) { };
+
+  virtual bool finalizeInlineAsm() { return true; }
 };
 
 } // End llvm namespace
Index: lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
+++ lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
@@ -33,6 +33,7 @@
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
 using namespace llvm;
 
 namespace {
@@ -114,14 +115,12 @@
                                                   OutContext, OutStreamer,
                                                   *MAI));
 
-  // FIXME: It would be nice if we can avoid createing a new instance of
-  // MCSubtargetInfo here given TargetSubtargetInfo is available. However,
-  // we have to watch out for asm directives which can change subtarget
-  // state. e.g. .code 16, .code 32.
-  OwningPtr<MCSubtargetInfo>
-    STI(TM.getTarget().createMCSubtargetInfo(TM.getTargetTriple(),
-                                             TM.getTargetCPU(),
-                                             TM.getTargetFeatureString()));
+  // Reuse the existing Subtarget, because the AsmParser will
+  // modify it.  For example, when switching between ARM and
+  // Thumb mode.
+  const MCSubtargetInfo* STC = TM.getSubtargetImpl();
+  MCSubtargetInfo* STI = const_cast<MCSubtargetInfo*>(STC);
+
   OwningPtr<MCTargetAsmParser>
     TAP(TM.getTarget().createMCAsmParser(*STI, *Parser, *MII));
   if (!TAP)
@@ -135,6 +134,10 @@
                         /*NoFinalize*/ true);
   if (Res && !HasDiagHandler)
     report_fatal_error("Error parsing inline asm\n");
+
+  // Give the target parser the opportunity to restore system state.
+  // For example, restore ARM mode.
+  TAP.get()->finalizeInlineAsm();
 }
 
 static void EmitMSInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
Index: lib/Target/ARM/AsmParser/ARMAsmParser.cpp
===================================================================
--- lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -79,6 +79,9 @@
 
   bool NextSymbolIsThumb;
 
+  // Was this parser initialized in thumb mode?
+  bool WasThumb;
+
   struct {
     ARMCC::CondCodes Cond;    // Condition for IT block.
     unsigned Mask:4;          // Condition mask for instructions.
@@ -277,6 +280,8 @@
     ITState.CurPosition = ~0U;
 
     NextSymbolIsThumb = false;
+
+    WasThumb = isThumb();
   }
 
   // Implementation of the MCTargetAsmParser interface:
@@ -295,6 +300,12 @@
                                bool MatchingInlineAsm);
   void onLabelParsed(MCSymbol *Symbol);
 
+  bool emitMode(bool WantThumb, SMLoc L);
+
+  bool finalizeInlineAsm() {
+    return emitMode(WasThumb, Parser.getTok().getLoc());
+  }
+
 };
 } // end anonymous namespace
 
@@ -7876,6 +7887,26 @@
   }
 }
 
+bool ARMAsmParser::emitMode(bool WantThumb, SMLoc L) {
+  if (WantThumb) {
+    if (!hasThumb())
+      return Error(L, "target does not support Thumb mode");
+
+    if (!isThumb())
+      SwitchMode();
+    getParser().getStreamer().EmitAssemblerFlag(MCAF_Code16);
+  } else {
+    if (!hasARM())
+      return Error(L, "target does not support ARM mode");
+
+    if (isThumb())
+      SwitchMode();
+    getParser().getStreamer().EmitAssemblerFlag(MCAF_Code32);
+  }
+
+  return false;
+}
+
 /// parseDirectiveThumbFunc
 ///  ::= .thumbfunc symbol_name
 bool ARMAsmParser::parseDirectiveThumbFunc(SMLoc L) {
@@ -7946,23 +7977,7 @@
     return Error(Parser.getTok().getLoc(), "unexpected token in directive");
   Parser.Lex();
 
-  if (Val == 16) {
-    if (!hasThumb())
-      return Error(L, "target does not support Thumb mode");
-
-    if (!isThumb())
-      SwitchMode();
-    getParser().getStreamer().EmitAssemblerFlag(MCAF_Code16);
-  } else {
-    if (!hasARM())
-      return Error(L, "target does not support ARM mode");
-
-    if (isThumb())
-      SwitchMode();
-    getParser().getStreamer().EmitAssemblerFlag(MCAF_Code32);
-  }
-
-  return false;
+  return emitMode(Val == 16, L);
 }
 
 /// parseDirectiveReq
Index: test/CodeGen/ARM/inlineasm-switch-mode.ll
===================================================================
--- /dev/null
+++ test/CodeGen/ARM/inlineasm-switch-mode.ll
@@ -0,0 +1,12 @@
+;RUN:  llc -mtriple=thumbv7-linux-gnueabi -filetype=obj < %s | llvm-objdump -arch=thumb -d - | FileCheck %s
+
+target triple = "thumbv7--linux-gnueabi"
+
+define hidden void @bah(i8* %start) #0 align 2 {
+  %1 = ptrtoint i8* %start to i32
+  %2 = tail call i32 asm sideeffect "@ Enter ARM Mode  \0A\09adr r3, 1f \0A\09bx  r3 \0A\09.align 2 \0A\09.code 32 \0A1:  push {r7} \0A\09mov r7, $4 \0A\09svc 0x0 \0A\09pop {r7} \0A\09@ Enter THUMB Mode\0A\09adr r3, 2f+1 \0A\09bx  r3 \0A\09.code 16 \0A2: \0A\09", "={r0},{r0},{r1},{r2},r,~{r3}"(i32 %1, i32 %1, i32 0, i32 983042) #3
+  ret void
+}
+; CHECK: $a
+; CHECK-NEXT: 04 70
+; CHECK-NEXT: 2d e5