Index: llvm/trunk/include/llvm/BinaryFormat/MachO.h
===================================================================
--- llvm/trunk/include/llvm/BinaryFormat/MachO.h
+++ llvm/trunk/include/llvm/BinaryFormat/MachO.h
@@ -486,7 +486,10 @@
   PLATFORM_IOS = 2,
   PLATFORM_TVOS = 3,
   PLATFORM_WATCHOS = 4,
-  PLATFORM_BRIDGEOS = 5
+  PLATFORM_BRIDGEOS = 5,
+  PLATFORM_IOSSIMULATOR = 7,
+  PLATFORM_TVOSSIMULATOR = 8,
+  PLATFORM_WATCHOSSIMULATOR = 9
 };
 
 // Values for tools enum in build_tool_version.
Index: llvm/trunk/include/llvm/Object/MachO.h
===================================================================
--- llvm/trunk/include/llvm/Object/MachO.h
+++ llvm/trunk/include/llvm/Object/MachO.h
@@ -616,6 +616,9 @@
     case MachO::PLATFORM_TVOS: return "tvos";
     case MachO::PLATFORM_WATCHOS: return "watchos";
     case MachO::PLATFORM_BRIDGEOS: return "bridgeos";
+    case MachO::PLATFORM_IOSSIMULATOR: return "iossimulator";
+    case MachO::PLATFORM_TVOSSIMULATOR: return "tvossimulator";
+    case MachO::PLATFORM_WATCHOSSIMULATOR: return "watchossimulator";
     default:
       std::string ret;
       raw_string_ostream ss(ret);
Index: llvm/trunk/lib/MC/MCAsmStreamer.cpp
===================================================================
--- llvm/trunk/lib/MC/MCAsmStreamer.cpp
+++ llvm/trunk/lib/MC/MCAsmStreamer.cpp
@@ -540,11 +540,14 @@
 
 static const char *getPlatformName(MachO::PlatformType Type) {
   switch (Type) {
-  case MachO::PLATFORM_MACOS:    return "macos";
-  case MachO::PLATFORM_IOS:      return "ios";
-  case MachO::PLATFORM_TVOS:     return "tvos";
-  case MachO::PLATFORM_WATCHOS:  return "watchos";
-  case MachO::PLATFORM_BRIDGEOS: return "bridgeos";
+  case MachO::PLATFORM_MACOS:            return "macos";
+  case MachO::PLATFORM_IOS:              return "ios";
+  case MachO::PLATFORM_TVOS:             return "tvos";
+  case MachO::PLATFORM_WATCHOS:          return "watchos";
+  case MachO::PLATFORM_BRIDGEOS:         return "bridgeos";
+  case MachO::PLATFORM_IOSSIMULATOR:     return "iossimulator";
+  case MachO::PLATFORM_TVOSSIMULATOR:    return "tvossimulator";
+  case MachO::PLATFORM_WATCHOSSIMULATOR: return "watchossimulator";
   }
   llvm_unreachable("Invalid Mach-O platform type");
 }
Index: llvm/trunk/lib/MC/MCParser/DarwinAsmParser.cpp
===================================================================
--- llvm/trunk/lib/MC/MCParser/DarwinAsmParser.cpp
+++ llvm/trunk/lib/MC/MCParser/DarwinAsmParser.cpp
@@ -1148,7 +1148,10 @@
   case MachO::PLATFORM_IOS:     return Triple::IOS;
   case MachO::PLATFORM_TVOS:    return Triple::TvOS;
   case MachO::PLATFORM_WATCHOS: return Triple::WatchOS;
-  case MachO::PLATFORM_BRIDGEOS: /* silence warning */break;
+  case MachO::PLATFORM_BRIDGEOS:         /* silence warning */ break;
+  case MachO::PLATFORM_IOSSIMULATOR:     /* silence warning */ break;
+  case MachO::PLATFORM_TVOSSIMULATOR:    /* silence warning */ break;
+  case MachO::PLATFORM_WATCHOSSIMULATOR: /* silence warning */ break;
   }
   llvm_unreachable("Invalid mach-o platform type");
 }