Stack realignment is a tristate. Add -mno-stackrealign to turn off all stack

realignment, even with locals with alignment exceeding the ABI guarantee.

llvm-svn: 145909

3 files changed, 14 insertions, 8 deletions

diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 3bc57e767c3..5ef72d486e5 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -289,11 +289,6 @@ bool EmitAssemblyHelper::AddEmitPasses(BackendAction Action,
 
   llvm::TargetOptions Options;
 
-  if (CodeGenOpts.RealignStack)
-    Options.RealignStack = true;
-  if (CodeGenOpts.StackAlignment)
-    Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
-
   // Set frame pointer elimination mode.
   if (!CodeGenOpts.DisableFPElim) {
     Options.NoFramePointerElim = false;
@@ -322,6 +317,8 @@ bool EmitAssemblyHelper::AddEmitPasses(BackendAction Action,
   Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
   Options.UnsafeFPMath = CodeGenOpts.UnsafeFPMath;
   Options.UseSoftFloat = CodeGenOpts.SoftFloat;
+  Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
+  Options.RealignStack = CodeGenOpts.StackRealignment;
 
   TargetMachine *TM = TheTarget->createTargetMachine(Triple, TargetOpts.CPU,
                                                      FeaturesStr, Options,
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 074be43fdb4..4987b0a81f0 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1796,8 +1796,17 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back(Args.MakeArgString(Twine(StackProtectorLevel)));
   }
 
-  if (Args.hasArg(options::OPT_mstackrealign))
-    CmdArgs.push_back("-mstackrealign");
+  // 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)) {
+    CmdArgs.push_back(Args.MakeArgString("-mstackrealign"));
+  }
+
   if (Args.hasArg(options::OPT_mstack_alignment)) {
     StringRef alignment = Args.getLastArgValue(options::OPT_mstack_alignment);
     CmdArgs.push_back(Args.MakeArgString("-mstack-alignment=" + alignment));
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index b89bf0808c9..2de9e8068c7 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1114,7 +1114,7 @@ static void ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.CoverageFile = Args.getLastArgValue(OPT_coverage_file);
   Opts.DebugCompilationDir = Args.getLastArgValue(OPT_fdebug_compilation_dir);
   Opts.LinkBitcodeFile = Args.getLastArgValue(OPT_mlink_bitcode_file);
-  Opts.RealignStack = Args.hasArg(OPT_mstackrealign);
+  Opts.StackRealignment = Args.hasArg(OPT_mstackrealign);
   if (Arg *A = Args.getLastArg(OPT_mstack_alignment)) {
     StringRef Val = A->getValue(Args);
     Val.getAsInteger(10, Opts.StackAlignment);