Index: clang/CMakeLists.txt
===================================================================
--- clang/CMakeLists.txt
+++ clang/CMakeLists.txt
@@ -306,6 +306,10 @@
     "Default architecture for OpenMP offloading to Nvidia GPUs." FORCE)
 endif()
 
+set(CLANG_SYSTEMZ_DEFAULT_ARCH "z10" CACHE STRING
+  "SystemZ Default Arch")
+add_definitions( -DCLANG_SYSTEMZ_DEFAULT_ARCH="${CLANG_SYSTEMZ_DEFAULT_ARCH}")
+
 set(CLANG_VENDOR ${PACKAGE_VENDOR} CACHE STRING
   "Vendor-specific text for showing with version information.")
 
Index: clang/lib/Driver/ToolChains/Arch/SystemZ.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Arch/SystemZ.cpp
+++ clang/lib/Driver/ToolChains/Arch/SystemZ.cpp
@@ -47,7 +47,7 @@
 
     return std::string(CPUName);
   }
-  return "z10";
+  return CLANG_SYSTEMZ_DEFAULT_ARCH;
 }
 
 void systemz::getSystemZTargetFeatures(const Driver &D, const ArgList &Args,