Index: cfe/trunk/include/clang/Frontend/CodeGenOptions.def
===================================================================
--- cfe/trunk/include/clang/Frontend/CodeGenOptions.def
+++ cfe/trunk/include/clang/Frontend/CodeGenOptions.def
@@ -150,7 +150,7 @@
 CODEGENOPT(VerifyModule      , 1, 1) ///< Control whether the module should be run
                                      ///< through the LLVM Verifier.
 
-CODEGENOPT(StackRealignment  , 1, 0) ///< Control whether to permit stack
+CODEGENOPT(StackRealignment  , 1, 0) ///< Control whether to force stack
                                      ///< realignment.
 CODEGENOPT(UseInitArray      , 1, 0) ///< Control whether to use .init_array or
                                      ///< .ctors.
Index: cfe/trunk/lib/CodeGen/CGCall.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CGCall.cpp
+++ cfe/trunk/lib/CodeGen/CGCall.cpp
@@ -1494,8 +1494,8 @@
     FuncAttrs.addAttribute("stack-protector-buffer-size",
                            llvm::utostr(CodeGenOpts.SSPBufferSize));
 
-    if (!CodeGenOpts.StackRealignment)
-      FuncAttrs.addAttribute("no-realign-stack");
+    if (CodeGenOpts.StackRealignment)
+      FuncAttrs.addAttribute("stackrealign");
 
     // 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: cfe/trunk/lib/Driver/Tools.cpp
===================================================================
--- cfe/trunk/lib/Driver/Tools.cpp
+++ cfe/trunk/lib/Driver/Tools.cpp
@@ -4326,14 +4326,8 @@
 
   // Translate -mstackrealign
   if (Args.hasFlag(options::OPT_mstackrealign, options::OPT_mno_stackrealign,
-                   false)) {
-    CmdArgs.push_back("-backend-option");
-    CmdArgs.push_back("-force-align-stack");
-  }
-  if (!Args.hasFlag(options::OPT_mno_stackrealign, options::OPT_mstackrealign,
-                    false)) {
+                   false))
     CmdArgs.push_back(Args.MakeArgString("-mstackrealign"));
-  }
 
   if (Args.hasArg(options::OPT_mstack_alignment)) {
     StringRef alignment = Args.getLastArgValue(options::OPT_mstack_alignment);
Index: cfe/trunk/test/CodeGen/stackrealign.c
===================================================================
--- cfe/trunk/test/CodeGen/stackrealign.c
+++ cfe/trunk/test/CodeGen/stackrealign.c
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 %s -emit-llvm -o - -mstackrealign | FileCheck %s -check-prefix=REALIGN
+// RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s -check-prefix=NO-REALIGN
+
+// REALIGN: attributes #{{[0-9]+}} = {{{.*}} "stackrealign"
+// NO-REALIGN-NOT: attributes #{{[0-9]+}} = {{{.*}} "stackrealign"
+
+void test1() {
+}
Index: cfe/trunk/test/Driver/rewrite-legacy-objc.m
===================================================================
--- cfe/trunk/test/Driver/rewrite-legacy-objc.m
+++ cfe/trunk/test/Driver/rewrite-legacy-objc.m
@@ -3,11 +3,11 @@
 // TEST0: clang{{.*}}" "-cc1"
 // TEST0: "-rewrite-objc"
 // FIXME: CHECK-NOT is broken somehow, it doesn't work here. Check adjacency instead.
-// TEST0: "-fmessage-length" "0" "-stack-protector" "1" "-mstackrealign" "-fblocks" "-fobjc-runtime=macosx-fragile" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fmax-type-align=16" "-fdiagnostics-show-option"
+// TEST0: "-fmessage-length" "0" "-stack-protector" "1" "-fblocks" "-fobjc-runtime=macosx-fragile" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fmax-type-align=16" "-fdiagnostics-show-option"
 // TEST0: rewrite-legacy-objc.m"
 // RUN: %clang -no-canonical-prefixes -target i386-apple-macosx10.9.0 -rewrite-legacy-objc %s -o - -### 2>&1 | \
 // RUN:   FileCheck -check-prefix=TEST1 %s
 // RUN: %clang -no-canonical-prefixes -target i386-apple-macosx10.6.0 -rewrite-legacy-objc %s -o - -### 2>&1 | \
 // RUN:   FileCheck -check-prefix=TEST2 %s
-// TEST1: "-fmessage-length" "0" "-stack-protector" "1" "-mstackrealign" "-fblocks" "-fobjc-runtime=macosx-fragile" "-fobjc-subscripting-legacy-runtime" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fmax-type-align=16" "-fdiagnostics-show-option"
-// TEST2: "-fmessage-length" "0" "-stack-protector" "1" "-mstackrealign" "-fblocks" "-fobjc-runtime=macosx-fragile" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fmax-type-align=16" "-fdiagnostics-show-option"
+// TEST1: "-fmessage-length" "0" "-stack-protector" "1" "-fblocks" "-fobjc-runtime=macosx-fragile" "-fobjc-subscripting-legacy-runtime" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fmax-type-align=16" "-fdiagnostics-show-option"
+// TEST2: "-fmessage-length" "0" "-stack-protector" "1" "-fblocks" "-fobjc-runtime=macosx-fragile" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fmax-type-align=16" "-fdiagnostics-show-option"
Index: cfe/trunk/test/Driver/rewrite-objc.m
===================================================================
--- cfe/trunk/test/Driver/rewrite-objc.m
+++ cfe/trunk/test/Driver/rewrite-objc.m
@@ -3,4 +3,4 @@
 // TEST0: clang{{.*}}" "-cc1"
 // TEST0: "-rewrite-objc"
 // FIXME: CHECK-NOT is broken somehow, it doesn't work here. Check adjacency instead.
-// TEST0: "-fmessage-length" "0" "-stack-protector" "1" "-mstackrealign" "-fblocks" "-fobjc-runtime=macosx" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fmax-type-align=16" "-fdiagnostics-show-option"
+// TEST0: "-fmessage-length" "0" "-stack-protector" "1" "-fblocks" "-fobjc-runtime=macosx" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fmax-type-align=16" "-fdiagnostics-show-option"
Index: cfe/trunk/test/Driver/stackrealign.c
===================================================================
--- cfe/trunk/test/Driver/stackrealign.c
+++ cfe/trunk/test/Driver/stackrealign.c
@@ -1,12 +1,6 @@
-// RUN: %clang -### %s 2>&1 | FileCheck %s -check-prefix=NORMAL
-// NORMAL-NOT: -force-align-stack
-// NORMAL: -mstackrealign
+// RUN: %clang -### %s 2>&1 | FileCheck %s -check-prefix=NO-REALIGN
+// RUN: %clang -### -mno-stackrealign -mstackrealign %s 2>&1 | FileCheck %s -check-prefix=REALIGN
+// RUN: %clang -### -mstackrealign -mno-stackrealign %s 2>&1 | FileCheck %s -check-prefix=NO-REALIGN
 
-// RUN: %clang -### -mstackrealign %s 2>&1 | FileCheck %s -check-prefix=MREALIGN
-// MREALIGN: -force-align-stack
-// MREALIGN: -mstackrealign
-
-// RUN: %clang -### -mno-stackrealign %s 2>&1 | \
-// RUN: FileCheck %s -check-prefix=MNOREALIGN
-// MNOREALIGN-NOT: -force-align-stack
-// MNOREALIGN-NOT: -mstackrealign
+// REALIGN: -mstackrealign
+// NO-REALIGN-NOT: -mstackrealign