Index: llvm/trunk/lib/Object/WindowsResource.cpp
===================================================================
--- llvm/trunk/lib/Object/WindowsResource.cpp
+++ llvm/trunk/lib/Object/WindowsResource.cpp
@@ -441,19 +441,7 @@
 void WindowsResourceCOFFWriter::writeCOFFHeader() {
   // Write the COFF header.
   auto *Header = reinterpret_cast<coff_file_header *>(BufferStart);
-  switch (MachineType) {
-  case COFF::IMAGE_FILE_MACHINE_ARMNT:
-    Header->Machine = COFF::IMAGE_FILE_MACHINE_ARMNT;
-    break;
-  case COFF::IMAGE_FILE_MACHINE_AMD64:
-    Header->Machine = COFF::IMAGE_FILE_MACHINE_AMD64;
-    break;
-  case COFF::IMAGE_FILE_MACHINE_I386:
-    Header->Machine = COFF::IMAGE_FILE_MACHINE_I386;
-    break;
-  default:
-    Header->Machine = COFF::IMAGE_FILE_MACHINE_UNKNOWN;
-  }
+  Header->Machine = MachineType;
   Header->NumberOfSections = 2;
   Header->TimeDateStamp = getTime();
   Header->PointerToSymbolTable = SymbolTableOffset;
@@ -714,8 +702,11 @@
     case COFF::IMAGE_FILE_MACHINE_I386:
       Reloc->Type = COFF::IMAGE_REL_I386_DIR32NB;
       break;
+    case COFF::IMAGE_FILE_MACHINE_ARM64:
+      Reloc->Type = COFF::IMAGE_REL_ARM64_ADDR32NB;
+      break;
     default:
-      Reloc->Type = 0;
+      llvm_unreachable("unknown machine type");
     }
     CurrentOffset += sizeof(coff_relocation);
   }
Index: llvm/trunk/test/tools/llvm-cvtres/machine.test
===================================================================
--- llvm/trunk/test/tools/llvm-cvtres/machine.test
+++ llvm/trunk/test/tools/llvm-cvtres/machine.test
@@ -22,6 +22,9 @@
 RUN: llvm-cvtres /machine:ARM /out:%t %p/Inputs/test_resource.res
 RUN: llvm-readobj -h -relocations %t | FileCheck %s -check-prefix=ARM
 
+RUN: llvm-cvtres /machine:ARM64 /out:%t %p/Inputs/test_resource.res
+RUN: llvm-readobj -h -relocations %t | FileCheck %s -check-prefix=ARM64
+
 X86:         Machine: IMAGE_FILE_MACHINE_I386 (0x14C)
 X86-DAG:   Relocations [
 X86-DAG:                 .rsrc$01 {
@@ -57,3 +60,15 @@
 ARM-NEXT:      0x1F8 IMAGE_REL_ARM_ADDR32NB $R000708
 ARM-NEXT:      0x1B8 IMAGE_REL_ARM_ADDR32NB $R000720
 ARM-NEXT:      0x188 IMAGE_REL_ARM_ADDR32NB $R000750
+
+ARM64:       Machine: IMAGE_FILE_MACHINE_ARM64 (0xAA64)
+ARM64-DAG: Relocations [
+ARM64-DAG:               .rsrc$01 {
+ARM64-NEXT:    0x1E8 IMAGE_REL_ARM64_ADDR32NB $R000000
+ARM64-NEXT:    0x198 IMAGE_REL_ARM64_ADDR32NB $R000018
+ARM64-NEXT:    0x1A8 IMAGE_REL_ARM64_ADDR32NB $R000340
+ARM64-NEXT:    0x1C8 IMAGE_REL_ARM64_ADDR32NB $R000668
+ARM64-NEXT:    0x1D8 IMAGE_REL_ARM64_ADDR32NB $R000698
+ARM64-NEXT:    0x1F8 IMAGE_REL_ARM64_ADDR32NB $R000708
+ARM64-NEXT:    0x1B8 IMAGE_REL_ARM64_ADDR32NB $R000720
+ARM64-NEXT:    0x188 IMAGE_REL_ARM64_ADDR32NB $R000750
Index: llvm/trunk/tools/llvm-cvtres/llvm-cvtres.cpp
===================================================================
--- llvm/trunk/tools/llvm-cvtres/llvm-cvtres.cpp
+++ llvm/trunk/tools/llvm-cvtres/llvm-cvtres.cpp
@@ -126,6 +126,7 @@
     std::string MachineString = InputArgs.getLastArgValue(OPT_MACHINE).upper();
     MachineType = StringSwitch<COFF::MachineTypes>(MachineString)
                       .Case("ARM", COFF::IMAGE_FILE_MACHINE_ARMNT)
+                      .Case("ARM64", COFF::IMAGE_FILE_MACHINE_ARM64)
                       .Case("X64", COFF::IMAGE_FILE_MACHINE_AMD64)
                       .Case("X86", COFF::IMAGE_FILE_MACHINE_I386)
                       .Default(COFF::IMAGE_FILE_MACHINE_UNKNOWN);
@@ -155,6 +156,9 @@
   if (Verbose) {
     outs() << "Machine: ";
     switch (MachineType) {
+    case COFF::IMAGE_FILE_MACHINE_ARM64:
+      outs() << "ARM64\n";
+      break;
     case COFF::IMAGE_FILE_MACHINE_ARMNT:
       outs() << "ARM\n";
       break;