Index: cfe/trunk/lib/Driver/ToolChain.cpp
===================================================================
--- cfe/trunk/lib/Driver/ToolChain.cpp
+++ cfe/trunk/lib/Driver/ToolChain.cpp
@@ -317,8 +317,7 @@
             ? tools::arm::getARMCPUForMArch(MArch, Triple).str()
             : tools::arm::getARMTargetCPU(MCPU, MArch, Triple);
     StringRef Suffix =
-      tools::arm::getLLVMArchSuffixForARM(CPU,
-                                          tools::arm::getARMArch(MArch, Triple));
+      tools::arm::getLLVMArchSuffixForARM(CPU, MArch, Triple);
     bool ThumbDefault = Suffix.startswith("v6m") || Suffix.startswith("v7m") ||
       Suffix.startswith("v7em") ||
       (Suffix.startswith("v7") && getTriple().isOSBinFormatMachO());
Index: cfe/trunk/lib/Driver/Tools.h
===================================================================
--- cfe/trunk/lib/Driver/Tools.h
+++ cfe/trunk/lib/Driver/Tools.h
@@ -246,7 +246,8 @@
 const std::string getARMArch(StringRef Arch,
                              const llvm::Triple &Triple);
 StringRef getARMCPUForMArch(StringRef Arch, const llvm::Triple &Triple);
-StringRef getLLVMArchSuffixForARM(StringRef CPU, StringRef Arch);
+StringRef getLLVMArchSuffixForARM(StringRef CPU, StringRef Arch,
+                                  const llvm::Triple &Triple);
 
 void appendEBLinkFlags(const llvm::opt::ArgList &Args, ArgStringList &CmdArgs,
                        const llvm::Triple &Triple);
Index: cfe/trunk/lib/Driver/Tools.cpp
===================================================================
--- cfe/trunk/lib/Driver/Tools.cpp
+++ cfe/trunk/lib/Driver/Tools.cpp
@@ -560,8 +560,7 @@
                             llvm::StringRef CPUName, llvm::StringRef ArchName,
                             const llvm::Triple &Triple) {
   std::string CPU = arm::getARMTargetCPU(CPUName, ArchName, Triple);
-  std::string Arch = arm::getARMArch(ArchName, Triple);
-  if (arm::getLLVMArchSuffixForARM(CPU, Arch).empty())
+  if (arm::getLLVMArchSuffixForARM(CPU, ArchName, Triple).empty())
     D.Diag(diag::err_drv_clang_unsupported) << A->getAsString(Args);
 }
 
@@ -6087,7 +6086,7 @@
     std::string CPU = llvm::sys::getHostCPUName();
     if (CPU != "generic") {
       // Translate the native cpu into the architecture suffix for that CPU.
-      StringRef Suffix = arm::getLLVMArchSuffixForARM(CPU, MArch);
+      StringRef Suffix = arm::getLLVMArchSuffixForARM(CPU, MArch, Triple);
       // If there is no valid architecture suffix for this CPU we don't know how
       // to handle it, so return no architecture.
       if (Suffix.empty())
@@ -6133,12 +6132,19 @@
 /// getLLVMArchSuffixForARM - Get the LLVM arch name to use for a particular
 /// CPU  (or Arch, if CPU is generic).
 // FIXME: This is redundant with -mcpu, why does LLVM use this.
-StringRef arm::getLLVMArchSuffixForARM(StringRef CPU, StringRef Arch) {
-  if (CPU == "generic")
-    return llvm::ARM::getSubArch(
-        llvm::ARM::parseArch(Arch));
-
-  unsigned ArchKind = llvm::ARM::parseCPUArch(CPU);
+StringRef arm::getLLVMArchSuffixForARM(StringRef CPU, StringRef Arch,
+                                       const llvm::Triple &Triple) {
+  unsigned ArchKind;
+  Arch = tools::arm::getARMArch(Arch, Triple);
+  if (CPU == "generic") {
+    ArchKind = llvm::ARM::parseArch(Arch);
+    if (ArchKind == llvm::ARM::AK_INVALID)
+      // In case of generic Arch, i.e. "arm",
+      // extract arch from default cpu of the Triple
+      ArchKind = llvm::ARM::parseCPUArch(Triple.getARMCPUForArch(Arch));
+  } else {
+    ArchKind = llvm::ARM::parseCPUArch(CPU);
+  }
   if (ArchKind == llvm::ARM::AK_INVALID)
     return "";
   return llvm::ARM::getSubArch(ArchKind);
Index: cfe/trunk/test/Driver/aarch64-cpus.c
===================================================================
--- cfe/trunk/test/Driver/aarch64-cpus.c
+++ cfe/trunk/test/Driver/aarch64-cpus.c
@@ -1,12 +1,17 @@
 // Check target CPUs are correctly passed.
 
 // RUN: %clang -target aarch64 -### -c %s 2>&1 | FileCheck -check-prefix=GENERIC %s
+// RUN: %clang -target aarch64 -mcpu=generic -### -c %s 2>&1 | FileCheck -check-prefix=GENERIC %s
 // RUN: %clang -target aarch64 -mlittle-endian -### -c %s 2>&1 | FileCheck -check-prefix=GENERIC %s
+// RUN: %clang -target aarch64 -mlittle-endian -mcpu=generic -### -c %s 2>&1 | FileCheck -check-prefix=GENERIC %s
 // RUN: %clang -target aarch64_be -mlittle-endian -### -c %s 2>&1 | FileCheck -check-prefix=GENERIC %s
+// RUN: %clang -target aarch64_be -mlittle-endian -mcpu=generic -### -c %s 2>&1 | FileCheck -check-prefix=GENERIC %s
 // GENERIC: "-cc1"{{.*}} "-triple" "aarch64{{.*}}" "-target-cpu" "generic"
 
 // RUN: %clang -target arm64 -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-GENERIC %s
+// RUN: %clang -target arm64 -mcpu=generic -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-GENERIC %s
 // RUN: %clang -target arm64 -mlittle-endian -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-GENERIC %s
+// RUN: %clang -target arm64 -mlittle-endian -mcpu-generic -### -c %s 2>&1 | FileCheck -check-prefix=ARM64-GENERIC %s
 
 // ARM64-GENERIC: "-cc1"{{.*}} "-triple" "arm64{{.*}}" "-target-cpu" "generic"
 
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
@@ -1,4 +1,16 @@
 // ================== Check default CPU on each major architecture
+// RUN: %clang -target arm -mcpu=generic -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-GENERIC %s
+// CHECK-GENERIC: "-cc1"{{.*}} "-triple" "armv4t-{{.*}} "-target-cpu" "generic"
+
+// RUN: %clang -target armeb -mcpu=generic -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-GENERIC %s
+// CHECK-BE-GENERIC: "-cc1"{{.*}} "-triple" "armebv4t-{{.*}} "-target-cpu" "generic"
+
+// RUN: %clang -target arm -mthumb -mcpu=generic -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-GENERIC-THUMB %s
+// CHECK-GENERIC-THUMB: "-cc1"{{.*}} "-triple" "thumbv4t-{{.*}} "-target-cpu" "generic"
+
+// RUN: %clang -target armeb -mthumb -mcpu=generic -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BE-GENERIC-THUMB %s
+// CHECK-BE-GENERIC-THUMB: "-cc1"{{.*}} "-triple" "thumbebv4t-{{.*}} "-target-cpu" "generic"
+
 // RUN: %clang -target armv4t -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V4T %s
 // RUN: %clang -target arm -march=armv4t -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-V4T %s
 // CHECK-V4T: "-cc1"{{.*}} "-triple" "armv4t-{{.*}} "-target-cpu" "arm7tdmi"