Index: lib/Driver/ToolChains/Arch/AArch64.cpp
===================================================================
--- lib/Driver/ToolChains/Arch/AArch64.cpp
+++ lib/Driver/ToolChains/Arch/AArch64.cpp
@@ -69,6 +69,9 @@
   std::pair<StringRef, StringRef> Split = Mcpu.split("+");
   CPU = Split.first;
 
+  if (CPU == "native")
+    CPU = llvm::sys::getHostCPUName();
+
   if (CPU == "generic") {
     Features.push_back("+neon");
   } else {
Index: test/Driver/aarch64-cpus.c
===================================================================
--- test/Driver/aarch64-cpus.c
+++ test/Driver/aarch64-cpus.c
@@ -15,6 +15,11 @@
 
 // ARM64-GENERIC: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "generic"
 
+// We cannot check much for -mcpu=native, but it should be replaced by either generic or a valid
+// Arm cpu string, depending on the host.
+// RUN: %clang -target arm64 -mcpu=native -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-NATIVE %s
+// ARM64-NATIVE-NOT: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "native"
+
 // RUN: %clang -target arm64-apple-darwin -arch arm64 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-DARWIN %s
 // ARM64-DARWIN: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "cyclone"