Index: cfe/trunk/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- cfe/trunk/lib/Driver/ToolChains/Clang.cpp
+++ cfe/trunk/lib/Driver/ToolChains/Clang.cpp
@@ -4547,6 +4547,7 @@
   Args.AddLastArg(CmdArgs, options::OPT_fdiagnostics_parseable_fixits);
   Args.AddLastArg(CmdArgs, options::OPT_ftime_report);
   Args.AddLastArg(CmdArgs, options::OPT_ftrapv);
+  Args.AddLastArg(CmdArgs, options::OPT_malign_double);
 
   if (Arg *A = Args.getLastArg(options::OPT_ftrapv_handler_EQ)) {
     CmdArgs.push_back("-ftrapv-handler");
Index: cfe/trunk/test/Driver/malign_double.c
===================================================================
--- cfe/trunk/test/Driver/malign_double.c
+++ cfe/trunk/test/Driver/malign_double.c
@@ -0,0 +1,5 @@
+// RUN: %clang -### -malign-double %s  2>&1 | FileCheck %s
+
+// Make sure -malign-double is passed through the driver.
+
+// CHECK: "-malign-double"