Index: include/clang/Driver/CC1Options.td
===================================================================
--- include/clang/Driver/CC1Options.td
+++ include/clang/Driver/CC1Options.td
@@ -170,6 +170,8 @@
   HelpText<"Emit an error if a C++ static local initializer would need a guard variable">;
 def no_implicit_float : Flag<["-"], "no-implicit-float">,
   HelpText<"Don't generate implicit floating point instructions">;
+def force_align_stack : Flag<["-"], "force-align-stack">,
+  HelpText<"Force realign the stack at entry to every function">;
 def fdump_vtable_layouts : Flag<["-"], "fdump-vtable-layouts">,
   HelpText<"Dump the layouts of all vtables that will be emitted in a translation unit">;
 def fmerge_functions : Flag<["-"], "fmerge-functions">,
Index: include/clang/Frontend/CodeGenOptions.def
===================================================================
--- include/clang/Frontend/CodeGenOptions.def
+++ include/clang/Frontend/CodeGenOptions.def
@@ -152,6 +152,8 @@
 
 CODEGENOPT(StackRealignment  , 1, 0) ///< Control whether to permit stack
                                      ///< realignment.
+CODEGENOPT(ForceAlignStack  , 1, 0) ///< Control whether to force stack
+                                    ///< realignment.
 CODEGENOPT(UseInitArray      , 1, 0) ///< Control whether to use .init_array or
                                      ///< .ctors.
 VALUE_CODEGENOPT(StackAlignment    , 32, 0) ///< Overrides default stack 
Index: lib/CodeGen/CGCall.cpp
===================================================================
--- lib/CodeGen/CGCall.cpp
+++ lib/CodeGen/CGCall.cpp
@@ -1491,6 +1491,8 @@
 
     if (!CodeGenOpts.StackRealignment)
       FuncAttrs.addAttribute("no-realign-stack");
+    else if (CodeGenOpts.ForceAlignStack)
+      FuncAttrs.addAttribute("force-align-stack");
 
     // Add target-cpu and target-features attributes to functions. If
     // we have a decl for the function and it has a target attribute then
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -4228,10 +4228,9 @@
 
   // Translate -mstackrealign
   if (Args.hasFlag(options::OPT_mstackrealign, options::OPT_mno_stackrealign,
-                   false)) {
-    CmdArgs.push_back("-backend-option");
-    CmdArgs.push_back("-force-align-stack");
-  }
+                   false))
+    CmdArgs.push_back(Args.MakeArgString("-force-align-stack"));
+
   if (!Args.hasFlag(options::OPT_mno_stackrealign, options::OPT_mstackrealign,
                     false)) {
     CmdArgs.push_back(Args.MakeArgString("-mstackrealign"));
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -569,6 +569,8 @@
   Opts.SSPBufferSize =
       getLastArgIntValue(Args, OPT_stack_protector_buffer_size, 8, Diags);
   Opts.StackRealignment = Args.hasArg(OPT_mstackrealign);
+  Opts.ForceAlignStack = Args.hasArg(OPT_force_align_stack);
+
   if (Arg *A = Args.getLastArg(OPT_mstack_alignment)) {
     StringRef Val = A->getValue();
     unsigned StackAlignment = Opts.StackAlignment;