AArch64::ArchKind's underlying type is uint64_t
diff --git a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
index ce7c534..6c5e437 100644
--- a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
@@ -94,7 +94,7 @@
     if (!llvm::AArch64::getArchFeatures(ArchKind, Features))
       return false;
 
-    unsigned Extension = llvm::AArch64::getDefaultExtensions(CPU, ArchKind);
+    uint64_t Extension = llvm::AArch64::getDefaultExtensions(CPU, ArchKind);
     if (!llvm::AArch64::getExtensionFeatures(Extension, Features))
       return false;
    }
diff --git a/llvm/include/llvm/Support/AArch64TargetParser.h b/llvm/include/llvm/Support/AArch64TargetParser.h
index b045e31..007a9ed 100644
--- a/llvm/include/llvm/Support/AArch64TargetParser.h
+++ b/llvm/include/llvm/Support/AArch64TargetParser.h
@@ -104,7 +104,7 @@
 };
 
 // FIXME: These should be moved to TargetTuple once it exists
-bool getExtensionFeatures(unsigned Extensions,
+bool getExtensionFeatures(uint64_t Extensions,
                           std::vector<StringRef> &Features);
 bool getArchFeatures(ArchKind AK, std::vector<StringRef> &Features);
 
@@ -117,7 +117,7 @@
 
 // Information by Name
 unsigned getDefaultFPU(StringRef CPU, ArchKind AK);
-unsigned getDefaultExtensions(StringRef CPU, ArchKind AK);
+uint64_t getDefaultExtensions(StringRef CPU, ArchKind AK);
 StringRef getDefaultCPU(StringRef Arch);
 ArchKind getCPUArchKind(StringRef CPU);
 
diff --git a/llvm/lib/Support/AArch64TargetParser.cpp b/llvm/lib/Support/AArch64TargetParser.cpp
index a6de446..82f7707 100644
--- a/llvm/lib/Support/AArch64TargetParser.cpp
+++ b/llvm/lib/Support/AArch64TargetParser.cpp
@@ -35,11 +35,11 @@
   .Default(ARM::FK_INVALID);
 }
 
-unsigned AArch64::getDefaultExtensions(StringRef CPU, AArch64::ArchKind AK) {
+uint64_t AArch64::getDefaultExtensions(StringRef CPU, AArch64::ArchKind AK) {
   if (CPU == "generic")
     return AArch64ARCHNames[static_cast<unsigned>(AK)].ArchBaseExtensions;
 
-  return StringSwitch<unsigned>(CPU)
+  return StringSwitch<uint64_t>(CPU)
 #define AARCH64_CPU_NAME(NAME, ID, DEFAULT_FPU, IS_DEFAULT, DEFAULT_EXT)       \
   .Case(NAME, AArch64ARCHNames[static_cast<unsigned>(ArchKind::ID)]            \
                       .ArchBaseExtensions |                                    \
@@ -59,7 +59,7 @@
   .Default(ArchKind::INVALID);
 }
 
-bool AArch64::getExtensionFeatures(unsigned Extensions,
+bool AArch64::getExtensionFeatures(uint64_t Extensions,
                                    std::vector<StringRef> &Features) {
   if (Extensions == AArch64::AEK_INVALID)
     return false;
diff --git a/llvm/unittests/Support/TargetParserTest.cpp b/llvm/unittests/Support/TargetParserTest.cpp
index f939275..bec8a39 100644
--- a/llvm/unittests/Support/TargetParserTest.cpp
+++ b/llvm/unittests/Support/TargetParserTest.cpp
@@ -782,12 +782,12 @@
 }
 
 bool testAArch64CPU(StringRef CPUName, StringRef ExpectedArch,
-                    StringRef ExpectedFPU, unsigned ExpectedFlags,
+                    StringRef ExpectedFPU, uint64_t ExpectedFlags,
                     StringRef CPUAttr) {
   AArch64::ArchKind AK = AArch64::parseCPUArch(CPUName);
   bool pass = AArch64::getArchName(AK).equals(ExpectedArch);
 
-  unsigned ExtKind = AArch64::getDefaultExtensions(CPUName, AK);
+  uint64_t ExtKind = AArch64::getDefaultExtensions(CPUName, AK);
   if (ExtKind > 1 && (ExtKind & AArch64::AEK_NONE))
     pass &= ((ExtKind ^ AArch64::AEK_NONE) == ExpectedFlags);
   else
@@ -1201,7 +1201,7 @@
 }
 
 TEST(TargetParserTest, AArch64ExtensionFeatures) {
-  std::vector<unsigned> Extensions = {
+  std::vector<uint64_t> Extensions = {
     AArch64::AEK_CRC,      AArch64::AEK_CRYPTO,
     AArch64::AEK_FP,       AArch64::AEK_SIMD,
     AArch64::AEK_FP16,     AArch64::AEK_PROFILE,
@@ -1214,7 +1214,7 @@
 
   std::vector<StringRef> Features;
 
-  unsigned ExtVal = 0;
+  uint64_t ExtVal = 0;
   for (auto Ext : Extensions)
     ExtVal |= Ext;