Index: cfe/trunk/lib/Driver/Tools.cpp
===================================================================
--- cfe/trunk/lib/Driver/Tools.cpp
+++ cfe/trunk/lib/Driver/Tools.cpp
@@ -1802,8 +1802,17 @@
                                 const ArgList &Args,
                                 std::vector<const char *> &Features) {
   std::pair<StringRef, StringRef> Split = March.split("+");
-  if (Split.first != "armv8-a")
+
+  if (Split.first == "armv8-a" ||
+      Split.first == "armv8a") {
+    // ok, no additional features.
+  } else if (
+      Split.first == "armv8.1-a" ||
+      Split.first == "armv8.1a" ) {
+    Features.push_back("+v8.1a");
+  } else {
     return false;
+  }
 
   if (Split.second.size() && !DecodeAArch64Features(D, Split.second, Features))
     return false;
Index: cfe/trunk/test/Driver/aarch64-cpus.c
===================================================================
--- cfe/trunk/test/Driver/aarch64-cpus.c
+++ cfe/trunk/test/Driver/aarch64-cpus.c
@@ -88,3 +88,26 @@
 // RUN: %clang -target aarch64 -mcpu=cortex-a72 -mtune=cortex-a53 -### -c %s 2>&1 | FileCheck -check-prefix=MCPU-MTUNE %s
 // RUN: %clang -target aarch64 -mtune=cortex-a53 -mcpu=cortex-a72  -### -c %s 2>&1 | FileCheck -check-prefix=MCPU-MTUNE %s
 // MCPU-MTUNE: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-cpu" "cortex-a53"
+
+// RUN: %clang -target aarch64 -march=armv8.1a -### -c %s 2>&1 | FileCheck -check-prefix=GENERICV81A %s
+// RUN: %clang -target aarch64 -march=armv8.1-a -### -c %s 2>&1 | FileCheck -check-prefix=GENERICV81A %s
+// RUN: %clang -target aarch64 -mlittle-endian -march=armv8.1a -### -c %s 2>&1 | FileCheck -check-prefix=GENERICV81A %s
+// RUN: %clang -target aarch64 -mlittle-endian -march=armv8.1-a -### -c %s 2>&1 | FileCheck -check-prefix=GENERICV81A %s
+// RUN: %clang -target aarch64_be -mlittle-endian -march=armv8.1a -### -c %s 2>&1 | FileCheck -check-prefix=GENERICV81A %s
+// RUN: %clang -target aarch64_be -mlittle-endian -march=armv8.1-a -### -c %s 2>&1 | FileCheck -check-prefix=GENERICV81A %s
+// GENERICV81A: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-cpu" "generic" "-target-feature" "+neon" "-target-feature" "+v8.1a"
+
+// RUN: %clang -target arm64 -march=armv8.1a -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-GENERICV81A %s
+// RUN: %clang -target arm64 -march=armv8.1-a -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-GENERICV81A %s
+// RUN: %clang -target arm64 -mlittle-endian -march=armv8.1a -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-GENERICV81A %s
+// RUN: %clang -target arm64 -mlittle-endian -march=armv8.1-a -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-GENERICV81A %s
+// ARM64-GENERICV81A: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "generic" "-target-feature" "+neon" "-target-feature" "+v8.1a"
+
+// RUN: %clang -target aarch64_be -march=armv8.1a -### -c %s 2>&1 | FileCheck -check-prefix=GENERICV81A-BE %s
+// RUN: %clang -target aarch64_be -march=armv8.1-a -### -c %s 2>&1 | FileCheck -check-prefix=GENERICV81A-BE %s
+// RUN: %clang -target aarch64 -mbig-endian -march=armv8.1a -### -c %s 2>&1 | FileCheck -check-prefix=GENERICV81A-BE %s
+// RUN: %clang -target aarch64 -mbig-endian -march=armv8.1-a -### -c %s 2>&1 | FileCheck -check-prefix=GENERICV81A-BE %s
+// RUN: %clang -target aarch64_be -mbig-endian -march=armv8.1a -### -c %s 2>&1 | FileCheck -check-prefix=GENERICV81A-BE %s
+// RUN: %clang -target aarch64_be -mbig-endian -march=armv8.1-a -### -c %s 2>&1 | FileCheck -check-prefix=GENERICV81A-BE %s
+// GENERICV81A-BE: "-cc1"{{.*}} "-triple" "aarch64_be{{.*}}" "-target-cpu" "generic" "-target-feature" "+neon" "-target-feature" "+v8.1a"
+
Index: cfe/trunk/test/Preprocessor/aarch64-target-features.c
===================================================================
--- cfe/trunk/test/Preprocessor/aarch64-target-features.c
+++ cfe/trunk/test/Preprocessor/aarch64-target-features.c
@@ -109,3 +109,11 @@
 // RUN: %clang -target aarch64 -march=armv8-a+neon -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-ERROR-NEON %s
 // RUN: %clang -target aarch64 -march=armv8-a+noneon -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-ERROR-NEON %s
 // CHECK-ERROR-NEON: error: [no]neon is not accepted as modifier, please use [no]simd instead
+
+// RUN: %clang -target aarch64 -march=armv8.1a+crypto -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V81A-FEATURE-1 %s
+// RUN: %clang -target aarch64 -march=armv8.1a+nocrypto -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V81A-FEATURE-2 %s
+// RUN: %clang -target aarch64 -march=armv8.1a+nosimd -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V81A-FEATURE-3 %s
+// CHECK-V81A-FEATURE-1: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+neon" "-target-feature" "+v8.1a" "-target-feature" "+crypto"
+// CHECK-V81A-FEATURE-2: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+neon" "-target-feature" "+v8.1a" "-target-feature" "-crypto"
+// CHECK-V81A-FEATURE-3: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-feature" "+v8.1a" "-target-feature" "-neon"
+