Index: llvm/trunk/docs/yaml2obj.rst
===================================================================
--- llvm/trunk/docs/yaml2obj.rst
+++ llvm/trunk/docs/yaml2obj.rst
@@ -65,6 +65,7 @@
                                  , IMAGE_FILE_MACHINE_AMD64
                                  , IMAGE_FILE_MACHINE_ARM
                                  , IMAGE_FILE_MACHINE_ARMNT
+                                 , IMAGE_FILE_MACHINE_ARM64
                                  , IMAGE_FILE_MACHINE_EBC
                                  , IMAGE_FILE_MACHINE_I386
                                  , IMAGE_FILE_MACHINE_IA64
Index: llvm/trunk/include/llvm/Support/COFF.h
===================================================================
--- llvm/trunk/include/llvm/Support/COFF.h
+++ llvm/trunk/include/llvm/Support/COFF.h
@@ -88,6 +88,7 @@
     IMAGE_FILE_MACHINE_AMD64     = 0x8664,
     IMAGE_FILE_MACHINE_ARM       = 0x1C0,
     IMAGE_FILE_MACHINE_ARMNT     = 0x1C4,
+    IMAGE_FILE_MACHINE_ARM64     = 0xAA64,
     IMAGE_FILE_MACHINE_EBC       = 0xEBC,
     IMAGE_FILE_MACHINE_I386      = 0x14C,
     IMAGE_FILE_MACHINE_IA64      = 0x200,
Index: llvm/trunk/lib/Object/COFFObjectFile.cpp
===================================================================
--- llvm/trunk/lib/Object/COFFObjectFile.cpp
+++ llvm/trunk/lib/Object/COFFObjectFile.cpp
@@ -744,6 +744,8 @@
     return "COFF-x86-64";
   case COFF::IMAGE_FILE_MACHINE_ARMNT:
     return "COFF-ARM";
+  case COFF::IMAGE_FILE_MACHINE_ARM64:
+    return "COFF-ARM64";
   default:
     return "COFF-<unknown arch>";
   }
@@ -757,6 +759,8 @@
     return Triple::x86_64;
   case COFF::IMAGE_FILE_MACHINE_ARMNT:
     return Triple::thumb;
+  case COFF::IMAGE_FILE_MACHINE_ARM64:
+    return Triple::aarch64;
   default:
     return Triple::UnknownArch;
   }
Index: llvm/trunk/lib/Object/COFFYAML.cpp
===================================================================
--- llvm/trunk/lib/Object/COFFYAML.cpp
+++ llvm/trunk/lib/Object/COFFYAML.cpp
@@ -56,6 +56,7 @@
   ECase(IMAGE_FILE_MACHINE_AMD64);
   ECase(IMAGE_FILE_MACHINE_ARM);
   ECase(IMAGE_FILE_MACHINE_ARMNT);
+  ECase(IMAGE_FILE_MACHINE_ARM64);
   ECase(IMAGE_FILE_MACHINE_EBC);
   ECase(IMAGE_FILE_MACHINE_I386);
   ECase(IMAGE_FILE_MACHINE_IA64);