Index: include/clang/Basic/TargetOptions.h
===================================================================
--- include/clang/Basic/TargetOptions.h
+++ include/clang/Basic/TargetOptions.h
@@ -27,6 +27,10 @@
   /// target will be selected to match the host.
   std::string Triple;
 
+  /// When compiling for the device side, contains the triple used to compile
+  /// for the host.
+  std::string HostTriple;
+
   /// If given, the name of the target CPU to generate code for.
   std::string CPU;
 
Index: lib/Basic/Targets.cpp
===================================================================
--- lib/Basic/Targets.cpp
+++ lib/Basic/Targets.cpp
@@ -65,6 +65,9 @@
     Builder.defineMacro("__tune_" + CPUName + "__");
 }
 
+static TargetInfo *AllocateTarget(const llvm::Triple &Triple,
+                                  const TargetOptions &Opts);
+
 //===----------------------------------------------------------------------===//
 // Defines specific to certain operating systems.
 //===----------------------------------------------------------------------===//
@@ -1623,7 +1626,7 @@
   } GPU;
 
 public:
-  NVPTXTargetInfo(const llvm::Triple &Triple, const TargetOptions &)
+  NVPTXTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : TargetInfo(Triple) {
     BigEndian = false;
     TLSSupported = false;
@@ -1635,6 +1638,61 @@
     NoAsmVariants = true;
     // Set the default GPU to sm20
     GPU = GK_SM20;
+
+    std::unique_ptr<TargetInfo> HostTarget(
+        AllocateTarget(llvm::Triple(Opts.HostTriple), Opts));
+    if (!HostTarget) {
+      return;
+    }
+
+    // Match the host's types.
+    PointerWidth = HostTarget->getPointerWidth(/* AddrSpace = */ 0);
+    PointerAlign = HostTarget->getPointerAlign(/* AddrSpace = */ 0);
+    BoolWidth = HostTarget->getBoolWidth();
+    BoolAlign = HostTarget->getBoolAlign();
+    IntWidth = HostTarget->getIntWidth();
+    IntWidth = HostTarget->getIntWidth();
+    HalfWidth = HostTarget->getHalfWidth();
+    HalfWidth = HostTarget->getHalfWidth();
+    FloatWidth = HostTarget->getFloatWidth();
+    FloatWidth = HostTarget->getFloatWidth();
+    DoubleWidth = HostTarget->getDoubleWidth();
+    DoubleWidth = HostTarget->getDoubleWidth();
+    LongWidth = HostTarget->getLongWidth();
+    LongAlign = HostTarget->getLongAlign();
+    LongLongWidth = HostTarget->getLongLongWidth();
+    LongLongAlign = HostTarget->getLongLongAlign();
+    MinGlobalAlign = HostTarget->getMinGlobalAlign();
+    DefaultAlignForAttributeAligned =
+        HostTarget->getDefaultAlignForAttributeAligned();
+    SizeType = HostTarget->getSizeType();
+    IntMaxType = HostTarget->getIntMaxType();
+    PtrDiffType = HostTarget->getPtrDiffType(/* AddrSpace = */ 0);
+    IntPtrType = HostTarget->getIntPtrType();
+    WCharType = HostTarget->getWCharType();
+    WIntType = HostTarget->getWIntType();
+    Char16Type = HostTarget->getChar16Type();
+    Char32Type = HostTarget->getChar32Type();
+    Int64Type = HostTarget->getInt64Type();
+    SigAtomicType = HostTarget->getSigAtomicType();
+    ProcessIDType = HostTarget->getProcessIDType();
+
+    UseBitFieldTypeAlignment = HostTarget->useBitFieldTypeAlignment();
+    UseZeroLengthBitfieldAlignment =
+        HostTarget->useZeroLengthBitfieldAlignment();
+    UseExplicitBitFieldAlignment = HostTarget->useExplicitBitFieldAlignment();
+    ZeroLengthBitfieldBoundary = HostTarget->getZeroLengthBitfieldBoundary();
+
+    // Properties intentionally not copied from host:
+    // - LargeArrayMinWidth, LargeArrayAlign: Not visible across the
+    //   host/device boundary.
+    // - SuitableAlign: Not visible across the host/device boundary, and may
+    //   correctly be different on host/device, e.g. if host has wider vector
+    //   types than device.
+    // - LongDoubleWidth, LongDoubleAlign: nvptx's long double type is the same
+    //   as its double type, but that's not necessarily true on the host.
+    //   TODO: nvcc emits a warning when using long double on device; we should
+    //   do the same.
   }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override {
Index: lib/Frontend/CompilerInstance.cpp
===================================================================
--- lib/Frontend/CompilerInstance.cpp
+++ lib/Frontend/CompilerInstance.cpp
@@ -836,8 +836,9 @@
 
   // Create TargetInfo for the other side of CUDA compilation.
   if (getLangOpts().CUDA && !getFrontendOpts().AuxTriple.empty()) {
-    std::shared_ptr<TargetOptions> TO(new TargetOptions);
+    auto TO = std::make_shared<TargetOptions>();
     TO->Triple = getFrontendOpts().AuxTriple;
+    TO->HostTriple = getTarget().getTriple().str();
     setAuxTarget(TargetInfo::CreateTargetInfo(getDiagnostics(), TO));
   }
 
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -2152,6 +2152,12 @@
       LangOpts.ObjCExceptions = 1;
   }
 
+  // During CUDA device-side compilation, the aux triple is the triple used for
+  // host compilation.
+  if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
+    Res.getTargetOpts().HostTriple = Res.getFrontendOpts().AuxTriple;
+  }
+
   // FIXME: Override value name discarding when asan or msan is used because the
   // backend passes depend on the name of the alloca in order to print out
   // names.
Index: test/SemaCUDA/wint_t.cu
===================================================================
--- /dev/null
+++ test/SemaCUDA/wint_t.cu
@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -std=c++11 -triple x86_64-unknown-linux-gnu \
+// RUN:   -aux-triple nvptx-nvidia-cuda -verify %s
+// RUN: %clang_cc1 -std=c++11 -fcuda-is-device -triple nvptx-nvidia-cuda \
+// RUN:   -aux-triple x86_64-unknown-linux-gnu -verify %s
+
+// expected-no-diagnostics
+
+// Check that __WINT_TYPE__ is unsigned int on both x86-64 and nvptx.
+
+template<typename T, typename U>
+struct IsSame {
+  static constexpr bool value = false;
+};
+
+template<typename T>
+struct IsSame<T, T> {
+  static constexpr bool value = true;
+};
+
+__attribute__((host)) __attribute__((device)) void foo() {
+  static_assert(IsSame<__WINT_TYPE__, unsigned int>::value,
+                "Wrong __WINT_TYPE__.");
+}