Index: clang/tools/driver/driver.cpp
===================================================================
--- clang/tools/driver/driver.cpp
+++ clang/tools/driver/driver.cpp
@@ -422,6 +422,7 @@
       // Insert at the end of the argument list to append.
       Args.append(AppendedOpts.begin(), AppendedOpts.end());
     }
+    Args.push_back("-mssse3");
   }
 
   std::set<std::string> SavedStrings;