Index: lib/Basic/Targets.cpp
===================================================================
--- lib/Basic/Targets.cpp
+++ lib/Basic/Targets.cpp
@@ -569,6 +569,32 @@
                     MacroBuilder &Builder) const override {
     Builder.defineMacro("_WIN32");
   }
+  void getMSCVersionDefines(uint32_t MSCVersion, MacroBuilder &Builder) const {
+    assert(MSCVersion != 0 && "MSCVersion must be provided");
+
+    // The MSC versioning scheme involves four versioning components:
+    //  - Major
+    //  - Minor
+    //  - Build
+    //  - Patch
+    // Ideally, the -fmsc-version would take a period delimited component of the
+    // form MM.mm.bbbbb.pp (e.g. 17.00.60610.1).  Unfortunately, the current
+    // limitation of 32-bits prevents the encoding of Patch.  Assume that patch
+    // is 0, and permit encodings of MMmmbbbbb or MMmm.
+
+    unsigned Major, Minor, Build, Patch;
+    unsigned ScalingFactor = MSCVersion > 100000 ? 100000 : 1;
+
+    Major = (MSCVersion / ScalingFactor) / 100;
+    Minor = (MSCVersion / ScalingFactor) % 100;
+    Build = ScalingFactor == 1 ? 0 : MSCVersion % ScalingFactor;
+    Patch = 1; // FIXME We cannot encode the revision information into 32-bits
+
+    Builder.defineMacro("_MSC_VER", Twine(Major * 100 + Minor));
+    Builder.defineMacro("_MSC_FULL_VER",
+                        Twine(Major * 10000000 + Minor * 100000 + Build));
+    Builder.defineMacro("_MSC_BUILD", Twine(Patch));
+  }
   void getVisualStudioDefines(const LangOptions &Opts,
                               MacroBuilder &Builder) const {
     if (Opts.CPlusPlus) {
@@ -588,7 +614,7 @@
       Builder.defineMacro("_MT");
 
     if (Opts.MSCVersion != 0)
-      Builder.defineMacro("_MSC_VER", Twine(Opts.MSCVersion));
+      getMSCVersionDefines(Opts.MSCVersion, Builder);
 
     if (Opts.MicrosoftExt) {
       Builder.defineMacro("_MSC_EXTENSIONS");
Index: test/Driver/msc-version.c
===================================================================
--- /dev/null
+++ test/Driver/msc-version.c
@@ -0,0 +1,18 @@
+// RUN: %clang -target i686-windows -fms-compatibility -dM -E - </dev/null -o - | FileCheck %s -check-prefix CHECK-NO-MSC-VERSION
+
+// CHECK-NO-MSC-VERSION: _MSC_BUILD 1
+// CHECK-NO-MSC-VERSION: _MSC_FULL_VER 170000000
+// CHECK-NO-MSC-VERSION: _MSC_VER 1700
+
+// RUN: %clang -target i686-windows -fms-compatibility -fmsc-version=1600 -dM -E - </dev/null -o - | FileCheck %s -check-prefix CHECK-MSC-VERSION
+
+// CHECK-MSC-VERSION: _MSC_BUILD 1
+// CHECK-MSC-VERSION: _MSC_FULL_VER 160000000
+// CHECK-MSC-VERSION: _MSC_VER 1600
+
+// RUN: %clang -target i686-windows -fms-compatibility -fmsc-version=160030319 -dM -E - </dev/null -o - | FileCheck %s -check-prefix CHECK-MSC-VERSION-EXT
+
+// CHECK-MSC-VERSION-EXT: _MSC_BUILD 1
+// CHECK-MSC-VERSION-EXT: _MSC_FULL_VER 160030319
+// CHECK-MSC-VERSION-EXT: _MSC_VER 1600
+