Index: cfe/trunk/lib/Driver/ToolChains/Arch/ARM.cpp
===================================================================
--- cfe/trunk/lib/Driver/ToolChains/Arch/ARM.cpp
+++ cfe/trunk/lib/Driver/ToolChains/Arch/ARM.cpp
@@ -87,6 +87,15 @@
   return true;
 }
 
+static void DecodeARMFeaturesFromCPU(const Driver &D, StringRef CPU,
+                                     std::vector<StringRef> &Features) {
+  if (CPU != "generic") {
+    llvm::ARM::ArchKind ArchKind = llvm::ARM::parseCPUArch(CPU);
+    unsigned Extension = llvm::ARM::getDefaultExtensions(CPU, ArchKind);
+    llvm::ARM::getExtensionFeatures(Extension, Features);
+  }
+}
+
 // Check if -march is valid by checking if it can be canonicalised and parsed.
 // getARMArch is used here instead of just checking the -march value in order
 // to handle -march=native correctly.
@@ -331,6 +340,8 @@
       for (auto &F : HostFeatures)
         Features.push_back(
             Args.MakeArgString((F.second ? "+" : "-") + F.first()));
+  } else if (!CPUName.empty()) {
+    DecodeARMFeaturesFromCPU(D, CPUName, Features);
   }
 
   // Honor -mfpu=. ClangAs gives preference to -Wa,-mfpu=.
Index: cfe/trunk/test/Driver/aarch64-cpus.c
===================================================================
--- cfe/trunk/test/Driver/aarch64-cpus.c
+++ cfe/trunk/test/Driver/aarch64-cpus.c
@@ -46,6 +46,19 @@
 // RUN: %clang -target arm64 -mlittle-endian -mtune=cortex-a53 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-CA53 %s
 // ARM64-CA53: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "cortex-a53"
 
+// RUN: %clang -target aarch64 -mcpu=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=CA55 %s
+// RUN: %clang -target aarch64 -mlittle-endian -mcpu=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=CA55 %s
+// RUN: %clang -target aarch64_be -mlittle-endian -mcpu=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=CA55 %s
+// RUN: %clang -target aarch64 -mtune=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=CA55 %s
+// RUN: %clang -target aarch64_be -mlittle-endian -mtune=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=CA55 %s
+// CA55: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-cpu" "cortex-a55"
+
+// RUN: %clang -target arm64 -mcpu=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-CA55 %s
+// RUN: %clang -target arm64 -mlittle-endian -mcpu=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-CA55 %s
+// RUN: %clang -target arm64 -mtune=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-CA55 %s
+// RUN: %clang -target arm64 -mlittle-endian -mtune=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-CA55 %s
+// ARM64-CA55: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "cortex-a55"
+
 // RUN: %clang -target aarch64 -mcpu=cortex-a57 -### -c %s 2>&1 | FileCheck -check-prefix=CA57 %s
 // RUN: %clang -target aarch64 -mlittle-endian -mcpu=cortex-a57 -### -c %s 2>&1 | FileCheck -check-prefix=CA57 %s
 // RUN: %clang -target aarch64_be -mlittle-endian -mcpu=cortex-a57 -### -c %s 2>&1 | FileCheck -check-prefix=CA57 %s
@@ -88,6 +101,20 @@
 // RUN: %clang -target arm64 -mlittle-endian -mtune=cortex-a73 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-CORTEX-A73 %s
 // ARM64-CORTEX-A73: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "cortex-a73"
 
+// RUN: %clang -target aarch64 -mcpu=cortex-a75 -### -c %s 2>&1 | FileCheck -check-prefix=CORTEX-A75 %s
+// RUN: %clang -target aarch64 -mlittle-endian -mcpu=cortex-a75 -### -c %s 2>&1 | FileCheck -check-prefix=CORTEX-A75 %s
+// RUN: %clang -target aarch64_be -mlittle-endian -mcpu=cortex-a75 -### -c %s 2>&1 | FileCheck -check-prefix=CORTEX-A75 %s
+// RUN: %clang -target aarch64 -mtune=cortex-a75 -### -c %s 2>&1 | FileCheck -check-prefix=CORTEX-A75 %s
+// RUN: %clang -target aarch64 -mlittle-endian -mtune=cortex-a75 -### -c %s 2>&1 | FileCheck -check-prefix=CORTEX-A75 %s
+// RUN: %clang -target aarch64_be -mlittle-endian -mtune=cortex-a75 -### -c %s 2>&1 | FileCheck -check-prefix=CORTEX-A75 %s
+// CORTEX-A75: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-cpu" "cortex-a75"
+
+// RUN: %clang -target arm64 -mcpu=cortex-a75 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-CORTEX-A75 %s
+// RUN: %clang -target arm64 -mlittle-endian -mcpu=cortex-a75 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-CORTEX-A75 %s
+// RUN: %clang -target arm64 -mtune=cortex-a75 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-CORTEX-A75 %s
+// RUN: %clang -target arm64 -mlittle-endian -mtune=cortex-a75 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-CORTEX-A75 %s
+// ARM64-CORTEX-A75: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "cortex-a75"
+
 // RUN: %clang -target aarch64 -mcpu=exynos-m1 -### -c %s 2>&1 | FileCheck -check-prefix=M1 %s
 // RUN: %clang -target aarch64 -mlittle-endian -mcpu=exynos-m1 -### -c %s 2>&1 | FileCheck -check-prefix=M1 %s
 // RUN: %clang -target aarch64_be -mlittle-endian -mcpu=exynos-m1 -### -c %s 2>&1 | FileCheck -check-prefix=M1 %s
@@ -193,6 +220,14 @@
 // RUN: %clang -target aarch64_be -mbig-endian -mtune=cortex-a53 -### -c %s 2>&1 | FileCheck -check-prefix=CA53-BE %s
 // CA53-BE: "-cc1"{{.*}} "-triple" "aarch64_be{{.*}}" "-target-cpu" "cortex-a53"
 
+// RUN: %clang -target aarch64_be -mcpu=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=CA55-BE %s
+// RUN: %clang -target aarch64 -mbig-endian -mcpu=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=CA55-BE %s
+// RUN: %clang -target aarch64_be -mbig-endian -mcpu=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=CA55-BE %s
+// RUN: %clang -target aarch64_be -mtune=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=CA55-BE %s
+// RUN: %clang -target aarch64 -mbig-endian -mtune=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=CA55-BE %s
+// RUN: %clang -target aarch64_be -mbig-endian -mtune=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=CA55-BE %s
+// CA55-BE: "-cc1"{{.*}} "-triple" "aarch64_be{{.*}}" "-target-cpu" "cortex-a55"
+
 // RUN: %clang -target aarch64_be -mcpu=cortex-a57 -### -c %s 2>&1 | FileCheck -check-prefix=CA57-BE %s
 // RUN: %clang -target aarch64 -mbig-endian -mcpu=cortex-a57 -### -c %s 2>&1 | FileCheck -check-prefix=CA57-BE %s
 // RUN: %clang -target aarch64_be -mbig-endian -mcpu=cortex-a57 -### -c %s 2>&1 | FileCheck -check-prefix=CA57-BE %s
Index: cfe/trunk/test/Driver/aarch64-dotprod.c
===================================================================
--- cfe/trunk/test/Driver/aarch64-dotprod.c
+++ cfe/trunk/test/Driver/aarch64-dotprod.c
@@ -0,0 +1,11 @@
+// RUN: %clang -### -target aarch64 %s 2>&1 | FileCheck %s --check-prefix=CHECK-NONE
+// RUN: %clang -### -target aarch64 -march=armv8.1a %s 2>&1 | FileCheck %s --check-prefix=CHECK-NONE
+// RUN: %clang -### -target aarch64 -march=armv8.2a %s 2>&1 | FileCheck %s --check-prefix=CHECK-NONE
+// RUN: %clang -### -target aarch64 -march=armv8.3a %s 2>&1 | FileCheck %s --check-prefix=CHECK-NONE
+// CHECK-NONE-NOT: "-target-feature" "+dotprod"
+
+// RUN: %clang -### -target aarch64 -march=armv8.2a+dotprod %s 2>&1 | FileCheck %s
+// RUN: %clang -### -target aarch64 -march=armv8.3a+dotprod %s 2>&1 | FileCheck %s
+// RUN: %clang -### -target aarch64 -mcpu=cortex-a75 %s 2>&1 | FileCheck %s
+// RUN: %clang -### -target aarch64 -mcpu=cortex-a55 %s 2>&1 | FileCheck %s
+// CHECK: "+dotprod"
Index: cfe/trunk/test/Driver/aarch64-ras.c
===================================================================
--- cfe/trunk/test/Driver/aarch64-ras.c
+++ cfe/trunk/test/Driver/aarch64-ras.c
@@ -1,5 +1,7 @@
 // RUN: %clang -target aarch64-none-none-eabi -march=armv8a+ras -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-RAS %s
 // RUN: %clang -target aarch64-none-none-eabi -mcpu=generic+ras -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-RAS %s
+// RUN: %clang -target aarch64-none-none-eabi -mcpu=cortex-a75 -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-RAS %s
+// RUN: %clang -target aarch64-none-none-eabi -mcpu=cortex-a55 -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-RAS %s
 // CHECK-RAS: "-target-feature" "+ras"
 
 // RUN: %clang -target aarch64-none-none-eabi -march=armv8a+noras -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-NORAS %s
Index: cfe/trunk/test/Driver/aarch64-rcpc.s
===================================================================
--- cfe/trunk/test/Driver/aarch64-rcpc.s
+++ cfe/trunk/test/Driver/aarch64-rcpc.s
@@ -0,0 +1,14 @@
+// RUN: %clang -### -target aarch64 %s 2>&1 | FileCheck --check-prefix=CHECK-NONE %s
+// RUN: %clang -### -target aarch64 -march=armv8.1a %s 2>&1 | FileCheck --check-prefix=CHECK-NONE %s
+// RUN: %clang -### -target aarch64 -march=armv8.2a %s 2>&1 | FileCheck --check-prefix=CHECK-NONE %s
+// CHECK-NONE-NOT: "-target-feature" "+rcpc"
+
+// RUN: %clang -### -target aarch64 -march=armv8.2a+rcpc %s 2>&1 | FileCheck %s
+// RUN: %clang -### -target aarch64 -march=armv8.3a+rcpc %s 2>&1 | FileCheck %s
+// RUN: %clang -### -target aarch64 -mcpu=cortex-a75 %s 2>&1 | FileCheck %s
+// RUN: %clang -### -target aarch64 -mcpu=cortex-a55 %s 2>&1 | FileCheck %s
+// CHECK: "-target-feature" "+rcpc"
+
+// RUN: %clang -### -target aarch64 -mcpu=cortex-a75+norcpc %s 2>&1 | FileCheck --check-prefix=CHECK-NO-RCPC %s
+// RUN: %clang -### -target aarch64 -mcpu=cortex-a55+norcpc %s 2>&1 | FileCheck --check-prefix=CHECK-NO-RCPC %s
+// CHECK-NO-RCPC: "-rcpc"
Index: cfe/trunk/test/Driver/arm-cortex-cpus.c
===================================================================
--- cfe/trunk/test/Driver/arm-cortex-cpus.c
+++ cfe/trunk/test/Driver/arm-cortex-cpus.c
@@ -507,6 +507,12 @@
 // RUN: %clang -target arm -mcpu=exynos-m3 -mlittle-endian -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV8A %s
 // CHECK-CPUV8A: "-cc1"{{.*}} "-triple" "armv8-{{.*}}
 
+// RUN: %clang -target arm -mcpu=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV82A %s
+// RUN: %clang -target arm -mcpu=cortex-a75 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV82A %s
+// RUN: %clang -target arm -mcpu=cortex-a55 -mlittle-endian -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV82A %s
+// RUN: %clang -target arm -mcpu=cortex-a75 -mlittle-endian -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV82A %s
+// CHECK-CPUV82A: "-cc1"{{.*}} "-triple" "armv8.2a-{{.*}}
+
 // RUN: %clang -target armeb -mcpu=cortex-a32 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A %s
 // RUN: %clang -target armeb -mcpu=cortex-a35 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A %s
 // RUN: %clang -target armeb -mcpu=cortex-a53 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A %s
@@ -527,6 +533,12 @@
 // RUN: %clang -target arm -mcpu=exynos-m3 -mbig-endian -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A %s
 // CHECK-BE-CPUV8A: "-cc1"{{.*}} "-triple" "armebv8-{{.*}}
 
+// RUN: %clang -target armeb -mcpu=cortex-a55 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV82A %s
+// RUN: %clang -target armeb -mcpu=cortex-a75 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV82A %s
+// RUN: %clang -target arm -mcpu=cortex-a55 -mbig-endian -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV82A %s
+// RUN: %clang -target arm -mcpu=cortex-a75 -mbig-endian -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV82A %s
+// CHECK-BE-CPUV82A: "-cc1"{{.*}} "-triple" "armebv8.2a-{{.*}}
+
 // RUN: %clang -target arm-linux-gnueabi -mcpu=cortex-r52 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV8R %s
 // CHECK-CPUV8R: "-cc1"{{.*}} "-triple" "armv8r-{{.*}}
 
@@ -550,6 +562,12 @@
 // RUN: %clang -target arm -mcpu=exynos-m3 -mlittle-endian -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV8A-THUMB %s
 // CHECK-CPUV8A-THUMB: "-cc1"{{.*}} "-triple" "thumbv8-{{.*}}
 
+// RUN: %clang -target arm -mcpu=cortex-a55 -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECKCPUV82A-THUMB %s
+// RUN: %clang -target arm -mcpu=cortex-a75 -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECKCPUV82A-THUMB %s
+// RUN: %clang -target arm -mcpu=cortex-a55 -mlittle-endian -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECKCPUV82A-THUMB %s
+// RUN: %clang -target arm -mcpu=cortex-a75 -mlittle-endian -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECKCPUV82A-THUMB %s
+// CHECKCPUV82A-THUMB: "-cc1"{{.*}} "-triple" "thumbv8.2a-{{.*}}
+
 // RUN: %clang -target armeb -mcpu=cortex-a32 -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A-THUMB %s
 // RUN: %clang -target armeb -mcpu=cortex-a35 -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A-THUMB %s
 // RUN: %clang -target armeb -mcpu=cortex-a53 -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A-THUMB %s
@@ -570,6 +588,12 @@
 // RUN: %clang -target arm -mcpu=exynos-m3 -mbig-endian -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV8A-THUMB %s
 // CHECK-BE-CPUV8A-THUMB: "-cc1"{{.*}} "-triple" "thumbebv8-{{.*}}
 
+// RUN: %clang -target armeb -mcpu=cortex-a55 -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV82A-THUMB %s
+// RUN: %clang -target armeb -mcpu=cortex-a75 -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV82A-THUMB %s
+// RUN: %clang -target arm -mcpu=cortex-a55 -mbig-endian -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV82A-THUMB %s
+// RUN: %clang -target arm -mcpu=cortex-a75 -mbig-endian -mthumb -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-CPUV82A-THUMB %s
+// CHECK-BE-CPUV82A-THUMB: "-cc1"{{.*}} "-triple" "thumbebv8.2a-{{.*}}
+
 // RUN: %clang -target armv8a-arm-none-eabi -mcpu=cortex-a73 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CORTEX-A73 %s
 // RUN: %clang -target armv8a-arm-none-eabi -mcpu=cortex-a73 -mfpu=crypto-neon-fp-armv8 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CORTEX-A73-MFPU %s
 // RUN: %clang -target armv8a-arm-none-eabi -mcpu=cortex-a73 -mfloat-abi=soft -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CORTEX-A73-SOFT %s
@@ -579,6 +603,15 @@
 // CHECK-CORTEX-A73-SOFT: "-target-feature" "+soft-float"
 // CHECK-CORTEX-A73-SOFT: "-target-feature" "+soft-float-abi"
 
+// RUN: %clang -target armv8a-arm-none-eabi -mcpu=cortex-a75 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CORTEX-A75 %s
+// RUN: %clang -target armv8a-arm-none-eabi -mcpu=cortex-a75 -mfpu=crypto-neon-fp-armv8 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CORTEX-A75-MFPU %s
+// RUN: %clang -target armv8a-arm-none-eabi -mcpu=cortex-a75 -mfloat-abi=soft -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CORTEX-A75-SOFT %s
+// CHECK-CORTEX-A75: "-cc1"{{.*}} "-triple" "armv8.2a-{{.*}} "-target-cpu" "cortex-a75"
+// CHECK-CORTEX-A75-MFPU: "-cc1"{{.*}} "-target-feature" "+fp-armv8"
+// CHECK-CORTEX-A75-MFPU: "-target-feature" "+crypto"
+// CHECK-CORTEX-A75-SOFT: "-target-feature" "+soft-float"
+// CHECK-CORTEX-A75-SOFT: "-target-feature" "+soft-float-abi"
+
 // RUN: %clang -target arm -mcpu=cortex-m23 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV8MBASE %s
 // CHECK-CPUV8MBASE:  "-cc1"{{.*}} "-triple" "thumbv8m.base-
 
Index: cfe/trunk/test/Driver/arm-dotprod.c
===================================================================
--- cfe/trunk/test/Driver/arm-dotprod.c
+++ cfe/trunk/test/Driver/arm-dotprod.c
@@ -0,0 +1,11 @@
+// RUN: %clang -### -target arm %s 2>&1 | FileCheck %s --check-prefix=CHECK-NONE
+// RUN: %clang -### -target arm -march=armv8.1a %s 2>&1 | FileCheck %s --check-prefix=CHECK-NONE
+// RUN: %clang -### -target arm -march=armv8.2a %s 2>&1 | FileCheck %s --check-prefix=CHECK-NONE
+// RUN: %clang -### -target arm -march=armv8.3a %s 2>&1 | FileCheck %s --check-prefix=CHECK-NONE
+// CHECK-NONE-NOT: "-target-feature" "+dotprod"
+
+// RUN: %clang -### -target arm -march=armv8.2a+dotprod %s 2>&1 | FileCheck %s
+// RUN: %clang -### -target arm -march=armv8.3a+dotprod %s 2>&1 | FileCheck %s
+// RUN: %clang -### -target arm -mcpu=cortex-a75 %s 2>&1 | FileCheck %s
+// RUN: %clang -### -target arm -mcpu=cortex-a55 %s 2>&1 | FileCheck %s
+// CHECK: "+dotprod"
Index: cfe/trunk/test/Driver/arm-ras.c
===================================================================
--- cfe/trunk/test/Driver/arm-ras.c
+++ cfe/trunk/test/Driver/arm-ras.c
@@ -1,5 +1,7 @@
 // RUN: %clang -target arm-none-none-eabi -march=armv8a+ras -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-RAS %s
 // RUN: %clang -target arm-none-none-eabi -mcpu=generic+ras -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-RAS %s
+// RUN: %clang -target arm-none-none-eabi -mcpu=cortex-a75 -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-RAS %s
+// RUN: %clang -target arm-none-none-eabi -mcpu=cortex-a55 -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-RAS %s
 // CHECK-RAS: "-target-feature" "+ras"
 
 // RUN: %clang -target arm-none-none-eabi -march=armv8a+noras -### -c %s 2>&1 | FileCheck --check-prefix=CHECK-NORAS %s