Index: cfe/trunk/include/clang/Basic/TargetInfo.h
===================================================================
--- cfe/trunk/include/clang/Basic/TargetInfo.h
+++ cfe/trunk/include/clang/Basic/TargetInfo.h
@@ -21,13 +21,14 @@
 #include "clang/Basic/TargetCXXABI.h"
 #include "clang/Basic/TargetOptions.h"
 #include "clang/Basic/VersionTuple.h"
-#include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/APInt.h"
+#include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Triple.h"
+#include "llvm/IR/DataLayout.h"
 #include "llvm/Support/DataTypes.h"
 #include <cassert>
 #include <string>
@@ -74,8 +75,7 @@
   unsigned short MaxVectorAlign;
   unsigned short MaxTLSAlign;
   unsigned short SimdDefaultAlign;
-  const char *DataLayoutString;
-  const char *UserLabelPrefix;
+  std::unique_ptr<llvm::DataLayout> DataLayout;
   const char *MCountName;
   const llvm::fltSemantics *HalfFormat, *FloatFormat, *DoubleFormat,
     *LongDoubleFormat;
@@ -95,6 +95,10 @@
   // TargetInfo Constructor.  Default initializes all fields.
   TargetInfo(const llvm::Triple &T);
 
+  void resetDataLayout(StringRef DL) {
+    DataLayout.reset(new llvm::DataLayout(DL));
+  }
+
 public:
   /// \brief Construct a target for the given options.
   ///
@@ -426,14 +430,6 @@
     return PointerWidth;
   }
 
-  /// \brief Returns the default value of the __USER_LABEL_PREFIX__ macro,
-  /// which is the prefix given to user symbols by default.
-  ///
-  /// On most platforms this is "_", but it is "" on some, and "." on others.
-  const char *getUserLabelPrefix() const {
-    return UserLabelPrefix;
-  }
-
   /// \brief Returns the name of the mcount instrumentation function.
   const char *getMCountName() const {
     return MCountName;
@@ -721,9 +717,9 @@
     return Triple;
   }
 
-  const char *getDataLayoutString() const {
-    assert(DataLayoutString && "Uninitialized DataLayoutString!");
-    return DataLayoutString;
+  const llvm::DataLayout &getDataLayout() const {
+    assert(DataLayout && "Uninitialized DataLayout!");
+    return *DataLayout;
   }
 
   struct GCCRegAlias {
Index: cfe/trunk/include/clang/CodeGen/BackendUtil.h
===================================================================
--- cfe/trunk/include/clang/CodeGen/BackendUtil.h
+++ cfe/trunk/include/clang/CodeGen/BackendUtil.h
@@ -35,8 +35,8 @@
 
   void EmitBackendOutput(DiagnosticsEngine &Diags, const CodeGenOptions &CGOpts,
                          const TargetOptions &TOpts, const LangOptions &LOpts,
-                         StringRef TDesc, llvm::Module *M, BackendAction Action,
-                         raw_pwrite_stream *OS);
+                         const llvm::DataLayout &TDesc, llvm::Module *M,
+                         BackendAction Action, raw_pwrite_stream *OS);
 }
 
 #endif
Index: cfe/trunk/lib/AST/Mangle.cpp
===================================================================
--- cfe/trunk/lib/AST/Mangle.cpp
+++ cfe/trunk/lib/AST/Mangle.cpp
@@ -126,9 +126,9 @@
     // llvm mangler on ELF is a nop, so we can just avoid adding the \01
     // marker.  We also avoid adding the marker if this is an alias for an
     // LLVM intrinsic.
-    StringRef UserLabelPrefix =
-        getASTContext().getTargetInfo().getUserLabelPrefix();
-    if (!UserLabelPrefix.empty() && !ALA->getLabel().startswith("llvm."))
+    char GlobalPrefix =
+        getASTContext().getTargetInfo().getDataLayout().getGlobalPrefix();
+    if (GlobalPrefix && !ALA->getLabel().startswith("llvm."))
       Out << '\01'; // LLVM IR Marker for __asm("foo")
 
     Out << ALA->getLabel();
Index: cfe/trunk/lib/Basic/TargetInfo.cpp
===================================================================
--- cfe/trunk/lib/Basic/TargetInfo.cpp
+++ cfe/trunk/lib/Basic/TargetInfo.cpp
@@ -72,8 +72,6 @@
   FloatFormat = &llvm::APFloat::IEEEsingle;
   DoubleFormat = &llvm::APFloat::IEEEdouble;
   LongDoubleFormat = &llvm::APFloat::IEEEdouble;
-  DataLayoutString = nullptr;
-  UserLabelPrefix = "_";
   MCountName = "mcount";
   RegParmMax = 0;
   SSERegParmMax = 0;
Index: cfe/trunk/lib/Basic/Targets.cpp
===================================================================
--- cfe/trunk/lib/Basic/Targets.cpp
+++ cfe/trunk/lib/Basic/Targets.cpp
@@ -102,9 +102,7 @@
 
 public:
   CloudABITargetInfo(const llvm::Triple &Triple)
-      : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
-  }
+      : OSTargetInfo<Target>(Triple) {}
 };
 
 static void getDarwinDefines(MacroBuilder &Builder, const LangOptions &Opts,
@@ -284,8 +282,6 @@
 public:
   DragonFlyBSDTargetInfo(const llvm::Triple &Triple)
       : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
-
     switch (Triple.getArch()) {
     default:
     case llvm::Triple::x86:
@@ -327,8 +323,6 @@
   }
 public:
   FreeBSDTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
-
     switch (Triple.getArch()) {
     default:
     case llvm::Triple::x86:
@@ -368,9 +362,7 @@
   }
 public:
   KFreeBSDTargetInfo(const llvm::Triple &Triple)
-      : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
-  }
+      : OSTargetInfo<Target>(Triple) {}
 };
 
 // Minix Target
@@ -392,9 +384,7 @@
     DefineStd(Builder, "unix", Opts);
   }
 public:
-  MinixTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
-  }
+  MinixTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {}
 };
 
 // Linux target
@@ -422,7 +412,6 @@
   }
 public:
   LinuxTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
     this->WIntType = TargetInfo::UnsignedInt;
 
     switch (Triple.getArch()) {
@@ -467,7 +456,6 @@
   }
 public:
   NetBSDTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
     this->MCountName = "_mcount";
   }
 };
@@ -488,7 +476,6 @@
   }
 public:
   OpenBSDTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
     this->TLSSupported = false;
 
       switch (Triple.getArch()) {
@@ -536,7 +523,6 @@
   }
 public:
   BitrigTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
     this->MCountName = "__mcount";
   }
 };
@@ -554,9 +540,7 @@
     Builder.defineMacro("__ELF__");
   }
 public:
-  PSPTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
-  }
+  PSPTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {}
 };
 
 // PS3 PPU Target
@@ -576,13 +560,12 @@
   }
 public:
   PS3PPUTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
     this->LongWidth = this->LongAlign = 32;
     this->PointerWidth = this->PointerAlign = 32;
     this->IntMaxType = TargetInfo::SignedLongLong;
     this->Int64Type = TargetInfo::SignedLongLong;
     this->SizeType = TargetInfo::UnsignedInt;
-    this->DataLayoutString = "E-m:e-p:32:32-i64:64-n32:64";
+    this->resetDataLayout("E-m:e-p:32:32-i64:64-n32:64");
   }
 };
 
@@ -604,7 +587,6 @@
 
     // On PS4, TLS variable cannot be aligned to more than 32 bytes (256 bits).
     this->MaxTLSAlign = 256;
-    this->UserLabelPrefix = "";
 
     // On PS4, do not honor explicit bit field alignment,
     // as in "__attribute__((aligned(2))) int b : 1;".
@@ -647,7 +629,6 @@
   }
 public:
   SolarisTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
     this->WCharType = this->SignedInt;
     // FIXME: WIntType should be SignedLong
   }
@@ -728,7 +709,6 @@
 
 public:
   NaClTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
     this->LongAlign = 32;
     this->LongWidth = 32;
     this->PointerAlign = 32;
@@ -748,14 +728,14 @@
     if (Triple.getArch() == llvm::Triple::arm) {
       // Handled in ARM's setABI().
     } else if (Triple.getArch() == llvm::Triple::x86) {
-      this->DataLayoutString = "e-m:e-p:32:32-i64:64-n8:16:32-S128";
+      this->resetDataLayout("e-m:e-p:32:32-i64:64-n8:16:32-S128");
     } else if (Triple.getArch() == llvm::Triple::x86_64) {
-      this->DataLayoutString = "e-m:e-p:32:32-i64:64-n8:16:32:64-S128";
+      this->resetDataLayout("e-m:e-p:32:32-i64:64-n8:16:32:64-S128");
     } else if (Triple.getArch() == llvm::Triple::mipsel) {
-      // Handled on mips' setDataLayoutString.
+      // Handled on mips' setDataLayout.
     } else {
       assert(Triple.getArch() == llvm::Triple::le32);
-      this->DataLayoutString = "e-p:32:32-i64:64";
+      this->resetDataLayout("e-p:32:32-i64:64");
     }
   }
 };
@@ -782,7 +762,6 @@
   explicit WebAssemblyOSTargetInfo(const llvm::Triple &Triple)
       : OSTargetInfo<Target>(Triple) {
     this->MCountName = "__mcount";
-    this->UserLabelPrefix = "";
     this->TheCXXABI.set(TargetCXXABI::WebAssembly);
   }
 };
@@ -1495,7 +1474,7 @@
 class PPC32TargetInfo : public PPCTargetInfo {
 public:
   PPC32TargetInfo(const llvm::Triple &Triple) : PPCTargetInfo(Triple) {
-    DataLayoutString = "E-m:e-p:32:32-i64:64-n32";
+    resetDataLayout("E-m:e-p:32:32-i64:64-n32");
 
     switch (getTriple().getOS()) {
     case llvm::Triple::Linux:
@@ -1534,10 +1513,10 @@
     Int64Type = SignedLong;
 
     if ((Triple.getArch() == llvm::Triple::ppc64le)) {
-      DataLayoutString = "e-m:e-i64:64-n32:64";
+      resetDataLayout("e-m:e-i64:64-n32:64");
       ABI = "elfv2";
     } else {
-      DataLayoutString = "E-m:e-i64:64-n32:64";
+      resetDataLayout("E-m:e-i64:64-n32:64");
       ABI = "elfv1";
     }
 
@@ -1580,7 +1559,7 @@
     PtrDiffType = SignedInt; // for http://llvm.org/bugs/show_bug.cgi?id=15726
     LongLongAlign = 32;
     SuitableAlign = 128;
-    DataLayoutString = "E-m:o-p:32:32-f64:32:64-n32";
+    resetDataLayout("E-m:o-p:32:32-f64:32:64-n32");
   }
   BuiltinVaListKind getBuiltinVaListKind() const override {
     return TargetInfo::CharPtrBuiltinVaList;
@@ -1594,7 +1573,7 @@
       : DarwinTargetInfo<PPC64TargetInfo>(Triple) {
     HasAlignMac68kSupport = true;
     SuitableAlign = 128;
-    DataLayoutString = "E-m:o-i64:64-n32:64";
+    resetDataLayout("E-m:o-i64:64-n32:64");
   }
 };
 
@@ -1736,7 +1715,7 @@
     SizeType = TargetInfo::UnsignedInt;
     PtrDiffType = TargetInfo::SignedInt;
     IntPtrType = TargetInfo::SignedInt;
-    DataLayoutString = "e-p:32:32-i64:64-v16:16-v32:32-n16:32:64";
+    resetDataLayout("e-p:32:32-i64:64-v16:16-v32:32-n16:32:64");
   }
 };
 
@@ -1747,7 +1726,7 @@
     SizeType = TargetInfo::UnsignedLong;
     PtrDiffType = TargetInfo::SignedLong;
     IntPtrType = TargetInfo::SignedLong;
-    DataLayoutString = "e-i64:64-v16:16-v32:32-n16:32:64";
+    resetDataLayout("e-i64:64-v16:16-v32:32-n16:32:64");
   }
 };
 
@@ -1806,13 +1785,13 @@
     : TargetInfo(Triple) {
 
     if (Triple.getArch() == llvm::Triple::amdgcn) {
-      DataLayoutString = DataLayoutStringSI;
+      resetDataLayout(DataLayoutStringSI);
       GPU = GK_SOUTHERN_ISLANDS;
       hasFP64 = true;
       hasFMAF = true;
       hasLDEXPF = true;
     } else {
-      DataLayoutString = DataLayoutStringR600;
+      resetDataLayout(DataLayoutStringR600);
       GPU = GK_R600;
       hasFP64 = false;
       hasFMAF = false;
@@ -1946,7 +1925,7 @@
     case GK_R700:
     case GK_EVERGREEN:
     case GK_NORTHERN_ISLANDS:
-      DataLayoutString = DataLayoutStringR600;
+      resetDataLayout(DataLayoutStringR600);
       hasFP64 = false;
       hasFMAF = false;
       hasLDEXPF = false;
@@ -1955,7 +1934,7 @@
     case GK_R700_DOUBLE_OPS:
     case GK_EVERGREEN_DOUBLE_OPS:
     case GK_CAYMAN:
-      DataLayoutString = DataLayoutStringR600DoubleOps;
+      resetDataLayout(DataLayoutStringR600DoubleOps);
       hasFP64 = true;
       hasFMAF = true;
       hasLDEXPF = false;
@@ -1963,7 +1942,7 @@
     case GK_SOUTHERN_ISLANDS:
     case GK_SEA_ISLANDS:
     case GK_VOLCANIC_ISLANDS:
-      DataLayoutString = DataLayoutStringSI;
+      resetDataLayout(DataLayoutStringSI);
       hasFP64 = true;
       hasFMAF = true;
       hasLDEXPF = true;
@@ -3749,7 +3728,7 @@
     LongDoubleWidth = 96;
     LongDoubleAlign = 32;
     SuitableAlign = 128;
-    DataLayoutString = "e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128";
+    resetDataLayout("e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128");
     SizeType = UnsignedInt;
     PtrDiffType = SignedInt;
     IntPtrType = SignedInt;
@@ -3846,7 +3825,7 @@
       UseSignedCharForObjCBool = false;
     SizeType = UnsignedLong;
     IntPtrType = SignedLong;
-    DataLayoutString = "e-m:o-p:32:32-f64:32:64-f80:128-n8:16:32-S128";
+    resetDataLayout("e-m:o-p:32:32-f64:32:64-f80:128-n8:16:32-S128");
     HasAlignMac68kSupport = true;
   }
 
@@ -3871,9 +3850,9 @@
     DoubleAlign = LongLongAlign = 64;
     bool IsWinCOFF =
         getTriple().isOSWindows() && getTriple().isOSBinFormatCOFF();
-    DataLayoutString = IsWinCOFF
-                           ? "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
-                           : "e-m:e-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32";
+    resetDataLayout(IsWinCOFF
+                        ? "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
+                        : "e-m:e-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32");
   }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override {
@@ -3952,7 +3931,7 @@
       : X86_32TargetInfo(Triple) {
     WCharType = UnsignedShort;
     DoubleAlign = LongLongAlign = 64;
-    DataLayoutString = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32";
+    resetDataLayout("e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32");
   }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override {
@@ -3975,7 +3954,6 @@
     IntPtrType = SignedLong;
     PtrDiffType = SignedLong;
     ProcessIDType = SignedLong;
-    this->UserLabelPrefix = "";
     this->TLSSupported = false;
   }
   void getTargetDefines(const LangOptions &Opts,
@@ -3992,9 +3970,7 @@
   MCUX86_32TargetInfo(const llvm::Triple &Triple) : X86_32TargetInfo(Triple) {
     LongDoubleWidth = 64;
     LongDoubleFormat = &llvm::APFloat::IEEEdouble;
-    DataLayoutString =
-        "e-m:e-p:32:32-i64:32-f64:32-f128:32-n8:16:32-a:0:32-S32";
-    UserLabelPrefix = "";
+    resetDataLayout("e-m:e-p:32:32-i64:32-f64:32-f128:32-n8:16:32-a:0:32-S32");
     WIntType = UnsignedInt;
   }
 
@@ -4029,8 +4005,6 @@
 
 public:
   RTEMSTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {
-    this->UserLabelPrefix = "";
-
     switch (Triple.getArch()) {
     default:
     case llvm::Triple::x86:
@@ -4057,7 +4031,6 @@
     SizeType = UnsignedLong;
     IntPtrType = SignedLong;
     PtrDiffType = SignedLong;
-    this->UserLabelPrefix = "";
   }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override {
@@ -4088,10 +4061,10 @@
     RegParmMax = 6;
 
     // Pointers are 32-bit in x32.
-    DataLayoutString = IsX32 ? "e-m:e-p:32:32-i64:64-f80:128-n8:16:32:64-S128"
-                             : IsWinCOFF
-                                   ? "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
-                                   : "e-m:e-i64:64-f80:128-n8:16:32:64-S128";
+    resetDataLayout(IsX32
+                        ? "e-m:e-p:32:32-i64:64-f80:128-n8:16:32:64-S128"
+                        : IsWinCOFF ? "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
+                                    : "e-m:e-i64:64-f80:128-n8:16:32:64-S128");
 
     // Use fpret only for long double.
     RealTypeUsesObjCFPRet = (1 << TargetInfo::LongDouble);
@@ -4168,7 +4141,6 @@
     SizeType = UnsignedLongLong;
     PtrDiffType = SignedLongLong;
     IntPtrType = SignedLongLong;
-    this->UserLabelPrefix = "";
   }
 
   void getTargetDefines(const LangOptions &Opts,
@@ -4246,7 +4218,6 @@
       : X86_64TargetInfo(Triple) {
     TLSSupported = false;
     WCharType = UnsignedShort;
-    UserLabelPrefix = "";
   }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override {
@@ -4274,7 +4245,7 @@
     llvm::Triple T = llvm::Triple(Triple);
     if (T.isiOS())
       UseSignedCharForObjCBool = false;
-    DataLayoutString = "e-m:o-i64:64-f80:128-n8:16:32:64-S128";
+    resetDataLayout("e-m:o-i64:64-f80:128-n8:16:32:64-S128");
   }
 
   bool handleTargetFeatures(std::vector<std::string> &Features,
@@ -4413,26 +4384,26 @@
     // Thumb1 add sp, #imm requires the immediate value be multiple of 4,
     // so set preferred for small types to 32.
     if (T.isOSBinFormatMachO()) {
-      DataLayoutString =
-          BigEndian ? "E-m:o-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
-                    : "e-m:o-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64";
+      resetDataLayout(BigEndian
+                          ? "E-m:o-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
+                          : "e-m:o-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64");
     } else if (T.isOSWindows()) {
       assert(!BigEndian && "Windows on ARM does not support big endian");
-      DataLayoutString = "e"
-                         "-m:w"
-                         "-p:32:32"
-                         "-i64:64"
-                         "-v128:64:128"
-                         "-a:0:32"
-                         "-n32"
-                         "-S64";
+      resetDataLayout("e"
+                      "-m:w"
+                      "-p:32:32"
+                      "-i64:64"
+                      "-v128:64:128"
+                      "-a:0:32"
+                      "-n32"
+                      "-S64");
     } else if (T.isOSNaCl()) {
       assert(!BigEndian && "NaCl on ARM does not support big endian");
-      DataLayoutString = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S128";
+      resetDataLayout("e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S128");
     } else {
-      DataLayoutString =
-          BigEndian ? "E-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
-                    : "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64";
+      resetDataLayout(BigEndian
+                          ? "E-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
+                          : "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64");
     }
 
     // FIXME: Enumerated types are variable width in straight AAPCS.
@@ -4468,17 +4439,17 @@
 
     if (T.isOSBinFormatMachO() && IsAAPCS16) {
       assert(!BigEndian && "AAPCS16 does not support big-endian");
-      DataLayoutString = "e-m:o-p:32:32-i64:64-a:0:32-n32-S128";
+      resetDataLayout("e-m:o-p:32:32-i64:64-a:0:32-n32-S128");
     } else if (T.isOSBinFormatMachO())
-      DataLayoutString =
+      resetDataLayout(
           BigEndian
               ? "E-m:o-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32"
-              : "e-m:o-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32";
+              : "e-m:o-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32");
     else
-      DataLayoutString =
+      resetDataLayout(
           BigEndian
               ? "E-m:e-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32"
-              : "e-m:e-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32";
+              : "e-m:e-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32");
 
     // FIXME: Override "preferred align" for double and long long.
   }
@@ -5243,7 +5214,6 @@
     : WindowsTargetInfo<ARMleTargetInfo>(Triple), Triple(Triple) {
     WCharType = UnsignedShort;
     SizeType = UnsignedInt;
-    UserLabelPrefix = "";
   }
   void getVisualStudioDefines(const LangOptions &Opts,
                               MacroBuilder &Builder) const {
@@ -5339,7 +5309,7 @@
     TLSSupported = false;
     WCharType = UnsignedShort;
     DoubleAlign = LongLongAlign = 64;
-    DataLayoutString = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64";
+    resetDataLayout("e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64");
   }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override {
@@ -5386,7 +5356,7 @@
 };
 
 class AArch64TargetInfo : public TargetInfo {
-  virtual void setDataLayoutString() = 0;
+  virtual void setDataLayout() = 0;
   static const TargetInfo::GCCRegAlias GCCRegAliases[];
   static const char *const GCCRegNames[];
 
@@ -5567,7 +5537,7 @@
         V8_1A = 1;
     }
 
-    setDataLayoutString();
+    setDataLayout();
 
     return true;
   }
@@ -5727,11 +5697,11 @@
 };
 
 class AArch64leTargetInfo : public AArch64TargetInfo {
-  void setDataLayoutString() override {
+  void setDataLayout() override {
     if (getTriple().isOSBinFormatMachO())
-      DataLayoutString = "e-m:o-i64:64-i128:128-n32:64-S128";
+      resetDataLayout("e-m:o-i64:64-i128:128-n32:64-S128");
     else
-      DataLayoutString = "e-m:e-i64:64-i128:128-n32:64-S128";
+      resetDataLayout("e-m:e-i64:64-i128:128-n32:64-S128");
   }
 
 public:
@@ -5747,9 +5717,9 @@
 };
 
 class AArch64beTargetInfo : public AArch64TargetInfo {
-  void setDataLayoutString() override {
+  void setDataLayout() override {
     assert(!getTriple().isOSBinFormatMachO());
-    DataLayoutString = "E-m:e-i64:64-i128:128-n32:64-S128";
+    resetDataLayout("E-m:e-i64:64-i128:128-n32:64-S128");
   }
 
 public:
@@ -5811,9 +5781,9 @@
     // Specify the vector alignment explicitly. For v512x1, the calculated
     // alignment would be 512*alignment(i1), which is 512 bytes, instead of
     // the required minimum of 64 bytes.
-    DataLayoutString = "e-m:e-p:32:32:32-a:0-n16:32-"
+    resetDataLayout("e-m:e-p:32:32:32-a:0-n16:32-"
         "i64:64:64-i32:32:32-i16:16:16-i1:8:8-f32:32:32-f64:64:64-"
-        "v32:32:32-v64:64:64-v512:512:512-v1024:1024:1024-v2048:2048:2048";
+        "v32:32:32-v64:64:64-v512:512:512-v1024:1024:1024-v2048:2048:2048");
     SizeType    = UnsignedInt;
     PtrDiffType = SignedInt;
     IntPtrType  = SignedInt;
@@ -6168,7 +6138,7 @@
 class SparcV8TargetInfo : public SparcTargetInfo {
 public:
   SparcV8TargetInfo(const llvm::Triple &Triple) : SparcTargetInfo(Triple) {
-    DataLayoutString = "E-m:e-p:32:32-i64:64-f128:64-n32-S64";
+    resetDataLayout("E-m:e-p:32:32-i64:64-f128:64-n32-S64");
     // NetBSD / OpenBSD use long (same as llvm default); everyone else uses int.
     switch (getTriple().getOS()) {
     default:
@@ -6209,7 +6179,7 @@
 class SparcV8elTargetInfo : public SparcV8TargetInfo {
  public:
   SparcV8elTargetInfo(const llvm::Triple &Triple) : SparcV8TargetInfo(Triple) {
-    DataLayoutString = "e-m:e-p:32:32-i64:64-f128:64-n32-S64";
+    resetDataLayout("e-m:e-p:32:32-i64:64-f128:64-n32-S64");
     BigEndian = false;
   }
 };
@@ -6219,7 +6189,7 @@
 public:
   SparcV9TargetInfo(const llvm::Triple &Triple) : SparcTargetInfo(Triple) {
     // FIXME: Support Sparc quad-precision long double?
-    DataLayoutString = "E-m:e-i64:64-n32:64-S128";
+    resetDataLayout("E-m:e-i64:64-n32:64-S128");
     // This is an LP64 platform.
     LongWidth = LongAlign = PointerWidth = PointerAlign = 64;
 
@@ -6280,7 +6250,7 @@
     LongDoubleFormat = &llvm::APFloat::IEEEquad;
     DefaultAlignForAttributeAligned = 64;
     MinGlobalAlign = 16;
-    DataLayoutString = "E-m:e-i1:8:16-i8:8:16-i64:64-f128:64-a:8:16-n32:64";
+    resetDataLayout("E-m:e-i1:8:16-i8:8:16-i64:64-f128:64-a:8:16-n32:64");
     MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 64;
   }
   void getTargetDefines(const LangOptions &Opts,
@@ -6355,8 +6325,8 @@
     // If we use the vector ABI, vector types are 64-bit aligned.
     if (HasVector) {
       MaxVectorAlign = 64;
-      DataLayoutString = "E-m:e-i1:8:16-i8:8:16-i64:64-f128:64"
-                         "-v128:64-a:8:16-n32:64";
+      resetDataLayout("E-m:e-i1:8:16-i8:8:16-i64:64-f128:64"
+                      "-v128:64-a:8:16-n32:64");
     }
     return true;
   }
@@ -6446,7 +6416,7 @@
     IntPtrType = SignedInt;
     PtrDiffType = SignedInt;
     SigAtomicType = SignedLong;
-    DataLayoutString = "e-m:e-p:16:16-i32:16:32-a:16-n8:16";
+    resetDataLayout("e-m:e-p:16:16-i32:16:32-a:16-n8:16");
   }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override {
@@ -6539,8 +6509,8 @@
     FloatFormat = &llvm::APFloat::IEEEsingle;
     DoubleFormat = &llvm::APFloat::IEEEsingle;
     LongDoubleFormat = &llvm::APFloat::IEEEsingle;
-    DataLayoutString = "E-p:32:32-i8:8:32-i16:16:32-i64:32"
-                       "-f64:32-v64:32-v128:32-a:0:32-n32";
+    resetDataLayout("E-p:32:32-i8:8:32-i16:16:32-i64:32"
+                    "-f64:32-v64:32-v128:32-a:0:32-n32");
     AddrSpaceMap = &TCEOpenCLAddrSpaceMap;
     UseAddrSpaceMapMangling = true;
   }
@@ -6580,10 +6550,10 @@
     RegParmMax = 5;
     if (Triple.getArch() == llvm::Triple::bpfeb) {
       BigEndian = true;
-      DataLayoutString = "E-m:e-p:64:64-i64:64-n32:64-S128";
+      resetDataLayout("E-m:e-p:64:64-i64:64-n32:64-S128");
     } else {
       BigEndian = false;
-      DataLayoutString = "e-m:e-p:64:64-i64:64-n32:64-S128";
+      resetDataLayout("e-m:e-p:64:64-i64:64-n32:64-S128");
     }
     MaxAtomicPromoteWidth = 64;
     MaxAtomicInlineWidth = 64;
@@ -6618,7 +6588,7 @@
 };
 
 class MipsTargetInfoBase : public TargetInfo {
-  virtual void setDataLayoutString() = 0;
+  virtual void setDataLayout() = 0;
 
   static const Builtin::Info BuiltinInfo[];
   std::string CPU;
@@ -6914,7 +6884,7 @@
         IsNan2008 = false;
     }
 
-    setDataLayoutString();
+    setDataLayout();
 
     return true;
   }
@@ -7021,8 +6991,8 @@
 };
 
 class Mips32EBTargetInfo : public Mips32TargetInfoBase {
-  void setDataLayoutString() override {
-    DataLayoutString = "E-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32-S64";
+  void setDataLayout() override {
+    resetDataLayout("E-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32-S64");
   }
 
 public:
@@ -7038,8 +7008,8 @@
 };
 
 class Mips32ELTargetInfo : public Mips32TargetInfoBase {
-  void setDataLayoutString() override {
-    DataLayoutString = "e-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32-S64";
+  void setDataLayout() override {
+    resetDataLayout("e-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32-S64");
   }
 
 public:
@@ -7179,12 +7149,11 @@
 };
 
 class Mips64EBTargetInfo : public Mips64TargetInfoBase {
-  void setDataLayoutString() override {
+  void setDataLayout() override {
     if (ABI == "n32")
-      DataLayoutString = "E-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32:64-S128";
+      resetDataLayout("E-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32:64-S128");
     else
-      DataLayoutString = "E-m:m-i8:8:32-i16:16:32-i64:64-n32:64-S128";
-
+      resetDataLayout("E-m:m-i8:8:32-i16:16:32-i64:64-n32:64-S128");
   }
 
 public:
@@ -7199,11 +7168,11 @@
 };
 
 class Mips64ELTargetInfo : public Mips64TargetInfoBase {
-  void setDataLayoutString() override {
+  void setDataLayout() override {
     if (ABI == "n32")
-      DataLayoutString = "e-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32:64-S128";
+      resetDataLayout("e-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32:64-S128");
     else
-      DataLayoutString = "e-m:m-i8:8:32-i16:16:32-i64:64-n32:64-S128";
+      resetDataLayout("e-m:m-i8:8:32-i16:16:32-i64:64-n32:64-S128");
   }
 public:
   Mips64ELTargetInfo(const llvm::Triple &Triple)
@@ -7223,7 +7192,6 @@
 public:
   PNaClTargetInfo(const llvm::Triple &Triple) : TargetInfo(Triple) {
     BigEndian = false;
-    this->UserLabelPrefix = "";
     this->LongAlign = 32;
     this->LongWidth = 32;
     this->PointerAlign = 32;
@@ -7295,7 +7263,7 @@
     NoAsmVariants = true;
     LongWidth = LongAlign = PointerWidth = PointerAlign = 64;
     MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 64;
-    DataLayoutString = "e-m:e-v128:32-v16:16-v32:32-v96:32-n8:16:32:64-S128";
+    resetDataLayout("e-m:e-v128:32-v16:16-v32:32-v96:32-n8:16:32:64-S128");
   }
 
   void getTargetDefines(const LangOptions &Opts,
@@ -7444,7 +7412,7 @@
   explicit WebAssembly32TargetInfo(const llvm::Triple &T)
       : WebAssemblyTargetInfo(T) {
     MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 32;
-    DataLayoutString = "e-m:e-p:32:32-i64:64-n32:64-S128";
+    resetDataLayout("e-m:e-p:32:32-i64:64-n32:64-S128");
   }
 
 protected:
@@ -7462,7 +7430,7 @@
     LongAlign = LongWidth = 64;
     PointerAlign = PointerWidth = 64;
     MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 64;
-    DataLayoutString = "e-m:e-p:64:64-i64:64-n32:64-S128";
+    resetDataLayout("e-m:e-p:64:64-i64:64-n32:64-S128");
   }
 
 protected:
@@ -7542,8 +7510,8 @@
     PointerWidth = PointerAlign = 32;
     SizeType = TargetInfo::UnsignedInt;
     PtrDiffType = IntPtrType = TargetInfo::SignedInt;
-    DataLayoutString = "e-p:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-"
-                       "v96:128-v192:256-v256:256-v512:512-v1024:1024";
+    resetDataLayout("e-p:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-"
+                    "v96:128-v192:256-v256:256-v512:512-v1024:1024");
   }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override {
@@ -7557,8 +7525,8 @@
     PointerWidth = PointerAlign = 64;
     SizeType = TargetInfo::UnsignedLong;
     PtrDiffType = IntPtrType = TargetInfo::SignedLong;
-    DataLayoutString = "e-i64:64-v16:16-v24:32-v32:32-v48:64-"
-                       "v96:128-v192:256-v256:256-v512:512-v1024:1024";
+    resetDataLayout("e-i64:64-v16:16-v24:32-v32:32-v48:64-"
+                    "v96:128-v192:256-v256:256-v512:512-v1024:1024");
   }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override {
@@ -7581,8 +7549,8 @@
     WCharType = UnsignedChar;
     WIntType = UnsignedInt;
     UseZeroLengthBitfieldAlignment = true;
-    DataLayoutString = "e-m:e-p:32:32-i1:8:32-i8:8:32-i16:16:32-i64:32"
-                       "-f64:32-a:0:32-n32";
+    resetDataLayout("e-m:e-p:32:32-i1:8:32-i8:8:32-i16:16:32-i64:32"
+                    "-f64:32-a:0:32-n32");
   }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override {
Index: cfe/trunk/lib/CodeGen/BackendUtil.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/BackendUtil.cpp
+++ cfe/trunk/lib/CodeGen/BackendUtil.cpp
@@ -710,22 +710,22 @@
 void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
                               const CodeGenOptions &CGOpts,
                               const clang::TargetOptions &TOpts,
-                              const LangOptions &LOpts, StringRef TDesc,
+                              const LangOptions &LOpts, const llvm::DataLayout &TDesc,
                               Module *M, BackendAction Action,
                               raw_pwrite_stream *OS) {
   EmitAssemblyHelper AsmHelper(Diags, CGOpts, TOpts, LOpts, M);
 
   AsmHelper.EmitAssembly(Action, OS);
 
-  // If an optional clang TargetInfo description string was passed in, use it to
-  // verify the LLVM TargetMachine's DataLayout.
-  if (AsmHelper.TM && !TDesc.empty()) {
+  // Verify clang's TargetInfo DataLayout against the LLVM TargetMachine's
+  // DataLayout.
+  if (AsmHelper.TM) {
     std::string DLDesc = M->getDataLayout().getStringRepresentation();
-    if (DLDesc != TDesc) {
+    if (DLDesc != TDesc.getStringRepresentation()) {
       unsigned DiagID = Diags.getCustomDiagID(
           DiagnosticsEngine::Error, "backend data layout '%0' does not match "
                                     "expected target description '%1'");
-      Diags.Report(DiagID) << DLDesc << TDesc;
+      Diags.Report(DiagID) << DLDesc << TDesc.getStringRepresentation();
     }
   }
 }
Index: cfe/trunk/lib/CodeGen/CodeGenAction.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CodeGenAction.cpp
+++ cfe/trunk/lib/CodeGen/CodeGenAction.cpp
@@ -174,7 +174,7 @@
       }
 
       EmitBackendOutput(Diags, CodeGenOpts, TargetOpts, LangOpts,
-                        C.getTargetInfo().getDataLayoutString(),
+                        C.getTargetInfo().getDataLayout(),
                         getModule(), Action, AsmOutStream);
 
       Ctx.setInlineAsmDiagnosticHandler(OldHandler, OldContext);
@@ -813,7 +813,7 @@
     LLVMContext &Ctx = TheModule->getContext();
     Ctx.setInlineAsmDiagnosticHandler(BitcodeInlineAsmDiagHandler);
     EmitBackendOutput(CI.getDiagnostics(), CI.getCodeGenOpts(), TargetOpts,
-                      CI.getLangOpts(), CI.getTarget().getDataLayoutString(),
+                      CI.getLangOpts(), CI.getTarget().getDataLayout(),
                       TheModule.get(), BA, OS);
     return;
   }
Index: cfe/trunk/lib/CodeGen/ModuleBuilder.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/ModuleBuilder.cpp
+++ cfe/trunk/lib/CodeGen/ModuleBuilder.cpp
@@ -98,7 +98,7 @@
       Ctx = &Context;
 
       M->setTargetTriple(Ctx->getTargetInfo().getTriple().getTriple());
-      M->setDataLayout(Ctx->getTargetInfo().getDataLayoutString());
+      M->setDataLayout(Ctx->getTargetInfo().getDataLayout());
       Builder.reset(new CodeGen::CodeGenModule(Context, HeaderSearchOpts,
                                                PreprocessorOpts, CodeGenOpts,
                                                *M, Diags, CoverageInfo));
Index: cfe/trunk/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
+++ cfe/trunk/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
@@ -162,7 +162,7 @@
     Ctx = &Context;
     VMContext.reset(new llvm::LLVMContext());
     M.reset(new llvm::Module(MainFileName, *VMContext));
-    M->setDataLayout(Ctx->getTargetInfo().getDataLayoutString());
+    M->setDataLayout(Ctx->getTargetInfo().getDataLayout());
     Builder.reset(new CodeGen::CodeGenModule(
         *Ctx, HeaderSearchOpts, PreprocessorOpts, CodeGenOpts, *M, Diags));
 
@@ -226,7 +226,7 @@
       return;
 
     M->setTargetTriple(Ctx.getTargetInfo().getTriple().getTriple());
-    M->setDataLayout(Ctx.getTargetInfo().getDataLayoutString());
+    M->setDataLayout(Ctx.getTargetInfo().getDataLayout());
 
     // PCH files don't have a signature field in the control block,
     // but LLVM detects DWO CUs by looking for a non-zero DWO id.
@@ -272,15 +272,15 @@
       llvm::SmallString<0> Buffer;
       llvm::raw_svector_ostream OS(Buffer);
       clang::EmitBackendOutput(Diags, CodeGenOpts, TargetOpts, LangOpts,
-                               Ctx.getTargetInfo().getDataLayoutString(),
-                               M.get(), BackendAction::Backend_EmitLL, &OS);
+                               Ctx.getTargetInfo().getDataLayout(), M.get(),
+                               BackendAction::Backend_EmitLL, &OS);
       llvm::dbgs() << Buffer;
     });
 
     // Use the LLVM backend to emit the pch container.
     clang::EmitBackendOutput(Diags, CodeGenOpts, TargetOpts, LangOpts,
-                             Ctx.getTargetInfo().getDataLayoutString(),
-                             M.get(), BackendAction::Backend_EmitObj, OS);
+                             Ctx.getTargetInfo().getDataLayout(), M.get(),
+                             BackendAction::Backend_EmitObj, OS);
 
     // Make sure the pch container hits disk.
     OS->flush();
Index: cfe/trunk/lib/Frontend/InitPreprocessor.cpp
===================================================================
--- cfe/trunk/lib/Frontend/InitPreprocessor.cpp
+++ cfe/trunk/lib/Frontend/InitPreprocessor.cpp
@@ -793,8 +793,8 @@
   DefineFastIntType(64, true, TI, Builder);
   DefineFastIntType(64, false, TI, Builder);
 
-  if (const char *Prefix = TI.getUserLabelPrefix())
-    Builder.defineMacro("__USER_LABEL_PREFIX__", Prefix);
+  char UserLabelPrefix[2] = {TI.getDataLayout().getGlobalPrefix(), 0};
+  Builder.defineMacro("__USER_LABEL_PREFIX__", UserLabelPrefix);
 
   if (LangOpts.FastMath || LangOpts.FiniteMathOnly)
     Builder.defineMacro("__FINITE_MATH_ONLY__", "1");
Index: cfe/trunk/lib/Index/CodegenNameGenerator.cpp
===================================================================
--- cfe/trunk/lib/Index/CodegenNameGenerator.cpp
+++ cfe/trunk/lib/Index/CodegenNameGenerator.cpp
@@ -31,7 +31,7 @@
 
   Implementation(ASTContext &Ctx)
     : MC(Ctx.createMangleContext()),
-      DL(Ctx.getTargetInfo().getDataLayoutString()) {}
+      DL(Ctx.getTargetInfo().getDataLayout()) {}
 
   bool writeName(const Decl *D, raw_ostream &OS) {
     // First apply frontend mangling.
@@ -76,8 +76,6 @@
 
     ASTContext &Ctx = ND->getASTContext();
     std::unique_ptr<MangleContext> M(Ctx.createMangleContext());
-    std::unique_ptr<llvm::DataLayout> DL(
-        new llvm::DataLayout(Ctx.getTargetInfo().getDataLayoutString()));
 
     std::vector<std::string> Manglings;
 
Index: cfe/trunk/test/Preprocessor/init.c
===================================================================
--- cfe/trunk/test/Preprocessor/init.c
+++ cfe/trunk/test/Preprocessor/init.c
@@ -423,7 +423,7 @@
 // AARCH64:#define __UINT_LEAST64_TYPE__ long unsigned int
 // AARCH64:#define __UINT_LEAST8_MAX__ 255
 // AARCH64:#define __UINT_LEAST8_TYPE__ unsigned char
-// AARCH64:#define __USER_LABEL_PREFIX__ _
+// AARCH64:#define __USER_LABEL_PREFIX__
 // AARCH64:#define __WCHAR_MAX__ 4294967295U
 // AARCH64:#define __WCHAR_TYPE__ unsigned int
 // AARCH64:#define __WCHAR_UNSIGNED__ 1
@@ -614,7 +614,7 @@
 // AARCH64-BE:#define __UINT_LEAST64_TYPE__ long unsigned int
 // AARCH64-BE:#define __UINT_LEAST8_MAX__ 255
 // AARCH64-BE:#define __UINT_LEAST8_TYPE__ unsigned char
-// AARCH64-BE:#define __USER_LABEL_PREFIX__ _
+// AARCH64-BE:#define __USER_LABEL_PREFIX__
 // AARCH64-BE:#define __WCHAR_MAX__ 4294967295U
 // AARCH64-BE:#define __WCHAR_TYPE__ unsigned int
 // AARCH64-BE:#define __WCHAR_UNSIGNED__ 1
@@ -1381,7 +1381,7 @@
 // ARM:#define __UINT_LEAST64_TYPE__ long long unsigned int
 // ARM:#define __UINT_LEAST8_MAX__ 255
 // ARM:#define __UINT_LEAST8_TYPE__ unsigned char
-// ARM:#define __USER_LABEL_PREFIX__ _
+// ARM:#define __USER_LABEL_PREFIX__
 // ARM:#define __WCHAR_MAX__ 4294967295U
 // ARM:#define __WCHAR_TYPE__ unsigned int
 // ARM:#define __WCHAR_WIDTH__ 32
@@ -1571,7 +1571,7 @@
 // ARM-BE:#define __UINT_LEAST64_TYPE__ long long unsigned int
 // ARM-BE:#define __UINT_LEAST8_MAX__ 255
 // ARM-BE:#define __UINT_LEAST8_TYPE__ unsigned char
-// ARM-BE:#define __USER_LABEL_PREFIX__ _
+// ARM-BE:#define __USER_LABEL_PREFIX__
 // ARM-BE:#define __WCHAR_MAX__ 4294967295U
 // ARM-BE:#define __WCHAR_TYPE__ unsigned int
 // ARM-BE:#define __WCHAR_WIDTH__ 32
@@ -2407,7 +2407,7 @@
 // I386:#define __UINT_LEAST64_TYPE__ long long unsigned int
 // I386:#define __UINT_LEAST8_MAX__ 255
 // I386:#define __UINT_LEAST8_TYPE__ unsigned char
-// I386:#define __USER_LABEL_PREFIX__ _
+// I386:#define __USER_LABEL_PREFIX__
 // I386:#define __WCHAR_MAX__ 2147483647
 // I386:#define __WCHAR_TYPE__ int
 // I386:#define __WCHAR_WIDTH__ 32
@@ -2998,7 +2998,7 @@
 // MIPS32BE:#define __UINT_LEAST64_TYPE__ long long unsigned int
 // MIPS32BE:#define __UINT_LEAST8_MAX__ 255
 // MIPS32BE:#define __UINT_LEAST8_TYPE__ unsigned char
-// MIPS32BE:#define __USER_LABEL_PREFIX__ _
+// MIPS32BE:#define __USER_LABEL_PREFIX__
 // MIPS32BE:#define __WCHAR_MAX__ 2147483647
 // MIPS32BE:#define __WCHAR_TYPE__ int
 // MIPS32BE:#define __WCHAR_WIDTH__ 32
@@ -3204,7 +3204,7 @@
 // MIPS32EL:#define __UINT_LEAST64_TYPE__ long long unsigned int
 // MIPS32EL:#define __UINT_LEAST8_MAX__ 255
 // MIPS32EL:#define __UINT_LEAST8_TYPE__ unsigned char
-// MIPS32EL:#define __USER_LABEL_PREFIX__ _
+// MIPS32EL:#define __USER_LABEL_PREFIX__
 // MIPS32EL:#define __WCHAR_MAX__ 2147483647
 // MIPS32EL:#define __WCHAR_TYPE__ int
 // MIPS32EL:#define __WCHAR_WIDTH__ 32
@@ -3507,7 +3507,7 @@
 // MIPSN32BE: #define __UINT_LEAST8_FMTx__ "hhx"
 // MIPSN32BE: #define __UINT_LEAST8_MAX__ 255
 // MIPSN32BE: #define __UINT_LEAST8_TYPE__ unsigned char
-// MIPSN32BE: #define __USER_LABEL_PREFIX__ _
+// MIPSN32BE: #define __USER_LABEL_PREFIX__
 // MIPSN32BE: #define __WCHAR_MAX__ 2147483647
 // MIPSN32BE: #define __WCHAR_TYPE__ int
 // MIPSN32BE: #define __WCHAR_WIDTH__ 32
@@ -3813,7 +3813,7 @@
 // MIPSN32EL: #define __UINT_LEAST8_FMTx__ "hhx"
 // MIPSN32EL: #define __UINT_LEAST8_MAX__ 255
 // MIPSN32EL: #define __UINT_LEAST8_TYPE__ unsigned char
-// MIPSN32EL: #define __USER_LABEL_PREFIX__ _
+// MIPSN32EL: #define __USER_LABEL_PREFIX__
 // MIPSN32EL: #define __WCHAR_MAX__ 2147483647
 // MIPSN32EL: #define __WCHAR_TYPE__ int
 // MIPSN32EL: #define __WCHAR_WIDTH__ 32
@@ -4023,7 +4023,7 @@
 // MIPS64BE:#define __UINT_LEAST64_TYPE__ long unsigned int
 // MIPS64BE:#define __UINT_LEAST8_MAX__ 255
 // MIPS64BE:#define __UINT_LEAST8_TYPE__ unsigned char
-// MIPS64BE:#define __USER_LABEL_PREFIX__ _
+// MIPS64BE:#define __USER_LABEL_PREFIX__
 // MIPS64BE:#define __WCHAR_MAX__ 2147483647
 // MIPS64BE:#define __WCHAR_TYPE__ int
 // MIPS64BE:#define __WCHAR_WIDTH__ 32
@@ -4232,7 +4232,7 @@
 // MIPS64EL:#define __UINT_LEAST64_TYPE__ long unsigned int
 // MIPS64EL:#define __UINT_LEAST8_MAX__ 255
 // MIPS64EL:#define __UINT_LEAST8_TYPE__ unsigned char
-// MIPS64EL:#define __USER_LABEL_PREFIX__ _
+// MIPS64EL:#define __USER_LABEL_PREFIX__
 // MIPS64EL:#define __WCHAR_MAX__ 2147483647
 // MIPS64EL:#define __WCHAR_TYPE__ int
 // MIPS64EL:#define __WCHAR_WIDTH__ 32
@@ -4652,7 +4652,7 @@
 // MSP430:#define __UINT_LEAST64_TYPE__ long long unsigned int
 // MSP430:#define __UINT_LEAST8_MAX__ 255
 // MSP430:#define __UINT_LEAST8_TYPE__ unsigned char
-// MSP430:#define __USER_LABEL_PREFIX__ _
+// MSP430:#define __USER_LABEL_PREFIX__
 // MSP430:#define __WCHAR_MAX__ 32767
 // MSP430:#define __WCHAR_TYPE__ int
 // MSP430:#define __WCHAR_WIDTH__ 16
@@ -4840,7 +4840,7 @@
 // NVPTX32:#define __UINT_LEAST64_TYPE__ long long unsigned int
 // NVPTX32:#define __UINT_LEAST8_MAX__ 255
 // NVPTX32:#define __UINT_LEAST8_TYPE__ unsigned char
-// NVPTX32:#define __USER_LABEL_PREFIX__ _
+// NVPTX32:#define __USER_LABEL_PREFIX__
 // NVPTX32:#define __WCHAR_MAX__ 2147483647
 // NVPTX32:#define __WCHAR_TYPE__ int
 // NVPTX32:#define __WCHAR_WIDTH__ 32
@@ -5027,7 +5027,7 @@
 // NVPTX64:#define __UINT_LEAST64_TYPE__ long unsigned int
 // NVPTX64:#define __UINT_LEAST8_MAX__ 255
 // NVPTX64:#define __UINT_LEAST8_TYPE__ unsigned char
-// NVPTX64:#define __USER_LABEL_PREFIX__ _
+// NVPTX64:#define __USER_LABEL_PREFIX__
 // NVPTX64:#define __WCHAR_MAX__ 2147483647
 // NVPTX64:#define __WCHAR_TYPE__ int
 // NVPTX64:#define __WCHAR_WIDTH__ 32
@@ -5219,7 +5219,7 @@
 // PPC603E:#define __UINT_LEAST64_TYPE__ long long unsigned int
 // PPC603E:#define __UINT_LEAST8_MAX__ 255
 // PPC603E:#define __UINT_LEAST8_TYPE__ unsigned char
-// PPC603E:#define __USER_LABEL_PREFIX__ _
+// PPC603E:#define __USER_LABEL_PREFIX__
 // PPC603E:#define __WCHAR_MAX__ 2147483647
 // PPC603E:#define __WCHAR_TYPE__ int
 // PPC603E:#define __WCHAR_WIDTH__ 32
@@ -5419,7 +5419,7 @@
 // PPC64:#define __UINT_LEAST64_TYPE__ long unsigned int
 // PPC64:#define __UINT_LEAST8_MAX__ 255
 // PPC64:#define __UINT_LEAST8_TYPE__ unsigned char
-// PPC64:#define __USER_LABEL_PREFIX__ _
+// PPC64:#define __USER_LABEL_PREFIX__
 // PPC64:#define __WCHAR_MAX__ 2147483647
 // PPC64:#define __WCHAR_TYPE__ int
 // PPC64:#define __WCHAR_WIDTH__ 32
@@ -5622,7 +5622,7 @@
 // PPC64LE:#define __UINT_LEAST64_TYPE__ long unsigned int
 // PPC64LE:#define __UINT_LEAST8_MAX__ 255
 // PPC64LE:#define __UINT_LEAST8_TYPE__ unsigned char
-// PPC64LE:#define __USER_LABEL_PREFIX__ _
+// PPC64LE:#define __USER_LABEL_PREFIX__
 // PPC64LE:#define __WCHAR_MAX__ 2147483647
 // PPC64LE:#define __WCHAR_TYPE__ int
 // PPC64LE:#define __WCHAR_WIDTH__ 32
@@ -6209,7 +6209,7 @@
 // PPC:#define __UINT_LEAST64_TYPE__ long long unsigned int
 // PPC:#define __UINT_LEAST8_MAX__ 255
 // PPC:#define __UINT_LEAST8_TYPE__ unsigned char
-// PPC:#define __USER_LABEL_PREFIX__ _
+// PPC:#define __USER_LABEL_PREFIX__
 // PPC:#define __WCHAR_MAX__ 2147483647
 // PPC:#define __WCHAR_TYPE__ int
 // PPC:#define __WCHAR_WIDTH__ 32
@@ -6788,7 +6788,7 @@
 // S390X:#define __UINT_LEAST64_TYPE__ long unsigned int
 // S390X:#define __UINT_LEAST8_MAX__ 255
 // S390X:#define __UINT_LEAST8_TYPE__ unsigned char
-// S390X:#define __USER_LABEL_PREFIX__ _
+// S390X:#define __USER_LABEL_PREFIX__
 // S390X:#define __WCHAR_MAX__ 2147483647
 // S390X:#define __WCHAR_TYPE__ int
 // S390X:#define __WCHAR_WIDTH__ 32
@@ -6797,7 +6797,10 @@
 // S390X:#define __s390__ 1
 // S390X:#define __s390x__ 1
 //
-// RUN: %clang_cc1 -E -dM -ffreestanding -triple=sparc-none-none < /dev/null | FileCheck -match-full-lines -check-prefix SPARC %s
+// RUN: %clang_cc1 -E -dM -ffreestanding -triple=sparc-none-none < /dev/null | FileCheck -match-full-lines -check-prefix SPARC -check-prefix SPARC-DEFAULT %s
+// RUN: %clang_cc1 -E -dM -ffreestanding -triple=sparc-rtems-elf < /dev/null | FileCheck -match-full-lines -check-prefix SPARC -check-prefix SPARC-DEFAULT %s
+// RUN: %clang_cc1 -E -dM -ffreestanding -triple=sparc-none-netbsd < /dev/null | FileCheck -match-full-lines -check-prefix SPARC -check-prefix SPARC-NETOPENBSD %s
+// RUN: %clang_cc1 -E -dM -ffreestanding -triple=sparc-none-openbsd < /dev/null | FileCheck -match-full-lines -check-prefix SPARC -check-prefix SPARC-NETOPENBSD %s
 //
 // SPARC-NOT:#define _LP64
 // SPARC:#define __BIGGEST_ALIGNMENT__ 8
@@ -6861,10 +6864,14 @@
 // SPARC:#define __INTMAX_MAX__ 9223372036854775807LL
 // SPARC:#define __INTMAX_TYPE__ long long int
 // SPARC:#define __INTMAX_WIDTH__ 64
-// SPARC:#define __INTPTR_FMTd__ "d"
-// SPARC:#define __INTPTR_FMTi__ "i"
-// SPARC:#define __INTPTR_MAX__ 2147483647
-// SPARC:#define __INTPTR_TYPE__ int
+// SPARC-DEFAULT:#define __INTPTR_FMTd__ "d"
+// SPARC-DEFAULT:#define __INTPTR_FMTi__ "i"
+// SPARC-DEFAULT:#define __INTPTR_MAX__ 2147483647
+// SPARC-DEFAULT:#define __INTPTR_TYPE__ int
+// SPARC-NETOPENBSD:#define __INTPTR_FMTd__ "ld"
+// SPARC-NETOPENBSD:#define __INTPTR_FMTi__ "li"
+// SPARC-NETOPENBSD:#define __INTPTR_MAX__ 2147483647L
+// SPARC-NETOPENBSD:#define __INTPTR_TYPE__ long int
 // SPARC:#define __INTPTR_WIDTH__ 32
 // SPARC:#define __INT_FAST16_FMTd__ "hd"
 // SPARC:#define __INT_FAST16_FMTi__ "hi"
@@ -6916,7 +6923,8 @@
 // SPARC:#define __LONG_MAX__ 2147483647L
 // SPARC-NOT:#define __LP64__
 // SPARC:#define __POINTER_WIDTH__ 32
-// SPARC:#define __PTRDIFF_TYPE__ int
+// SPARC-DEFAULT:#define __PTRDIFF_TYPE__ int
+// SPARC-NETOPENBSD:#define __PTRDIFF_TYPE__ long int
 // SPARC:#define __PTRDIFF_WIDTH__ 32
 // SPARC:#define __REGISTER_PREFIX__
 // SPARC:#define __SCHAR_MAX__ 127
@@ -6935,8 +6943,10 @@
 // SPARC:#define __SIZEOF_SIZE_T__ 4
 // SPARC:#define __SIZEOF_WCHAR_T__ 4
 // SPARC:#define __SIZEOF_WINT_T__ 4
-// SPARC:#define __SIZE_MAX__ 4294967295U
-// SPARC:#define __SIZE_TYPE__ unsigned int
+// SPARC-DEFAULT:#define __SIZE_MAX__ 4294967295U
+// SPARC-DEFAULT:#define __SIZE_TYPE__ unsigned int
+// SPARC-NETOPENBSD:#define __SIZE_MAX__ 4294967295UL
+// SPARC-NETOPENBSD:#define __SIZE_TYPE__ long unsigned int
 // SPARC:#define __SIZE_WIDTH__ 32
 // SPARC:#define __UINT16_C_SUFFIX__
 // SPARC:#define __UINT16_MAX__ 65535
@@ -6954,8 +6964,10 @@
 // SPARC:#define __UINTMAX_MAX__ 18446744073709551615ULL
 // SPARC:#define __UINTMAX_TYPE__ long long unsigned int
 // SPARC:#define __UINTMAX_WIDTH__ 64
-// SPARC:#define __UINTPTR_MAX__ 4294967295U
-// SPARC:#define __UINTPTR_TYPE__ unsigned int
+// SPARC-DEFAULT:#define __UINTPTR_MAX__ 4294967295U
+// SPARC-DEFAULT:#define __UINTPTR_TYPE__ unsigned int
+// SPARC-NETOPENBSD:#define __UINTPTR_MAX__ 4294967295UL
+// SPARC-NETOPENBSD:#define __UINTPTR_TYPE__ long unsigned int
 // SPARC:#define __UINTPTR_WIDTH__ 32
 // SPARC:#define __UINT_FAST16_MAX__ 65535
 // SPARC:#define __UINT_FAST16_TYPE__ unsigned short
@@ -6973,7 +6985,7 @@
 // SPARC:#define __UINT_LEAST64_TYPE__ long long unsigned int
 // SPARC:#define __UINT_LEAST8_MAX__ 255
 // SPARC:#define __UINT_LEAST8_TYPE__ unsigned char
-// SPARC:#define __USER_LABEL_PREFIX__ _
+// SPARC:#define __USER_LABEL_PREFIX__
 // SPARC:#define __VERSION__ "4.2.1 Compatible{{.*}}
 // SPARC:#define __WCHAR_MAX__ 2147483647
 // SPARC:#define __WCHAR_TYPE__ int
@@ -6984,16 +6996,6 @@
 // SPARC:#define __sparc__ 1
 // SPARC:#define __sparcv8 1
 // SPARC:#define sparc 1
-// 
-// RUN: %clang_cc1 -E -dM -ffreestanding -triple=sparc-none-netbsd < /dev/null | FileCheck -match-full-lines -check-prefix SPARC-NETOPENBSD %s
-// RUN: %clang_cc1 -E -dM -ffreestanding -triple=sparc-none-openbsd < /dev/null | FileCheck -match-full-lines -check-prefix SPARC-NETOPENBSD %s
-// SPARC-NETOPENBSD:#define __INTPTR_FMTd__ "ld"
-// SPARC-NETOPENBSD:#define __INTPTR_FMTi__ "li"
-// SPARC-NETOPENBSD:#define __INTPTR_MAX__ 2147483647L
-// SPARC-NETOPENBSD:#define __INTPTR_TYPE__ long int
-// SPARC-NETOPENBSD:#define __PTRDIFF_TYPE__ long int
-// SPARC-NETOPENBSD:#define __SIZE_TYPE__ long unsigned int
-// SPARC-NETOPENBSD:#define __UINTPTR_TYPE__ long unsigned int
 
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=tce-none-none < /dev/null | FileCheck -match-full-lines -check-prefix TCE %s
 //
@@ -7152,7 +7154,7 @@
 // TCE:#define __UINT_LEAST32_TYPE__ unsigned int
 // TCE:#define __UINT_LEAST8_MAX__ 255
 // TCE:#define __UINT_LEAST8_TYPE__ unsigned char
-// TCE:#define __USER_LABEL_PREFIX__ _
+// TCE:#define __USER_LABEL_PREFIX__
 // TCE:#define __WCHAR_MAX__ 2147483647
 // TCE:#define __WCHAR_TYPE__ int
 // TCE:#define __WCHAR_WIDTH__ 32
@@ -7346,7 +7348,7 @@
 // X86_64:#define __UINT_LEAST64_TYPE__ long unsigned int
 // X86_64:#define __UINT_LEAST8_MAX__ 255
 // X86_64:#define __UINT_LEAST8_TYPE__ unsigned char
-// X86_64:#define __USER_LABEL_PREFIX__ _
+// X86_64:#define __USER_LABEL_PREFIX__
 // X86_64:#define __WCHAR_MAX__ 2147483647
 // X86_64:#define __WCHAR_TYPE__ int
 // X86_64:#define __WCHAR_WIDTH__ 32
@@ -7548,7 +7550,7 @@
 // X32:#define __UINT_LEAST64_TYPE__ long long unsigned int
 // X32:#define __UINT_LEAST8_MAX__ 255
 // X32:#define __UINT_LEAST8_TYPE__ unsigned char
-// X32:#define __USER_LABEL_PREFIX__ _
+// X32:#define __USER_LABEL_PREFIX__
 // X32:#define __WCHAR_MAX__ 2147483647
 // X32:#define __WCHAR_TYPE__ int
 // X32:#define __WCHAR_WIDTH__ 32
Index: cfe/trunk/unittests/Basic/SourceManagerTest.cpp
===================================================================
--- cfe/trunk/unittests/Basic/SourceManagerTest.cpp
+++ cfe/trunk/unittests/Basic/SourceManagerTest.cpp
@@ -23,7 +23,6 @@
 #include "llvm/Config/llvm-config.h"
 #include "gtest/gtest.h"
 
-using namespace llvm;
 using namespace clang;
 
 namespace {
@@ -73,7 +72,8 @@
   const char *source =
     "#define M(x) [x]\n"
     "M(foo)";
-  std::unique_ptr<MemoryBuffer> Buf = MemoryBuffer::getMemBuffer(source);
+  std::unique_ptr<llvm::MemoryBuffer> Buf =
+      llvm::MemoryBuffer::getMemBuffer(source);
   FileID mainFileID = SourceMgr.createFileID(std::move(Buf));
   SourceMgr.setMainFileID(mainFileID);
 
@@ -126,7 +126,8 @@
     "int x;\n"
     "int y;";
 
-  std::unique_ptr<MemoryBuffer> Buf = MemoryBuffer::getMemBuffer(Source);
+  std::unique_ptr<llvm::MemoryBuffer> Buf =
+      llvm::MemoryBuffer::getMemBuffer(Source);
   FileID MainFileID = SourceMgr.createFileID(std::move(Buf));
   SourceMgr.setMainFileID(MainFileID);
 
@@ -185,8 +186,10 @@
     "#define CONCAT(X, Y) X##Y\n"
     "CONCAT(1,1)\n";
 
-  std::unique_ptr<MemoryBuffer> HeaderBuf = MemoryBuffer::getMemBuffer(header);
-  std::unique_ptr<MemoryBuffer> MainBuf = MemoryBuffer::getMemBuffer(main);
+  std::unique_ptr<llvm::MemoryBuffer> HeaderBuf =
+      llvm::MemoryBuffer::getMemBuffer(header);
+  std::unique_ptr<llvm::MemoryBuffer> MainBuf =
+      llvm::MemoryBuffer::getMemBuffer(main);
   FileID mainFileID = SourceMgr.createFileID(std::move(MainBuf));
   SourceMgr.setMainFileID(mainFileID);
 
@@ -284,8 +287,10 @@
     "#define INC2 </test-header.h>\n"
     "#include M(INC2)\n";
 
-  std::unique_ptr<MemoryBuffer> HeaderBuf = MemoryBuffer::getMemBuffer(header);
-  std::unique_ptr<MemoryBuffer> MainBuf = MemoryBuffer::getMemBuffer(main);
+  std::unique_ptr<llvm::MemoryBuffer> HeaderBuf =
+      llvm::MemoryBuffer::getMemBuffer(header);
+  std::unique_ptr<llvm::MemoryBuffer> MainBuf =
+      llvm::MemoryBuffer::getMemBuffer(main);
   SourceMgr.setMainFileID(SourceMgr.createFileID(std::move(MainBuf)));
 
   const FileEntry *headerFile = FileMgr.getVirtualFile("/test-header.h",
Index: cfe/trunk/unittests/Lex/LexerTest.cpp
===================================================================
--- cfe/trunk/unittests/Lex/LexerTest.cpp
+++ cfe/trunk/unittests/Lex/LexerTest.cpp
@@ -22,7 +22,6 @@
 #include "clang/Lex/PreprocessorOptions.h"
 #include "gtest/gtest.h"
 
-using namespace llvm;
 using namespace clang;
 
 namespace {
@@ -61,7 +60,8 @@
 
   std::vector<Token> CheckLex(StringRef Source,
                               ArrayRef<tok::TokenKind> ExpectedTokens) {
-    std::unique_ptr<MemoryBuffer> Buf = MemoryBuffer::getMemBuffer(Source);
+    std::unique_ptr<llvm::MemoryBuffer> Buf =
+        llvm::MemoryBuffer::getMemBuffer(Source);
     SourceMgr.setMainFileID(SourceMgr.createFileID(std::move(Buf)));
 
     VoidModuleLoader ModLoader;
Index: cfe/trunk/unittests/Lex/PPConditionalDirectiveRecordTest.cpp
===================================================================
--- cfe/trunk/unittests/Lex/PPConditionalDirectiveRecordTest.cpp
+++ cfe/trunk/unittests/Lex/PPConditionalDirectiveRecordTest.cpp
@@ -22,7 +22,6 @@
 #include "clang/Lex/PreprocessorOptions.h"
 #include "gtest/gtest.h"
 
-using namespace llvm;
 using namespace clang;
 
 namespace {
@@ -89,7 +88,8 @@
       "#endif\n"
       "9\n";
 
-  std::unique_ptr<MemoryBuffer> Buf = MemoryBuffer::getMemBuffer(source);
+  std::unique_ptr<llvm::MemoryBuffer> Buf =
+      llvm::MemoryBuffer::getMemBuffer(source);
   SourceMgr.setMainFileID(SourceMgr.createFileID(std::move(Buf)));
 
   VoidModuleLoader ModLoader;