Add support for -fno-optimize-sibling-calls. Currently only implemented in the

X86 backend in LLVM.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148689 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Driver/CC1Options.td b/include/clang/Driver/CC1Options.td
index 3b87dd2ab56dbcab9befcc2f363a031942b4da26..3d599061b061e41c5e1c2c5594ed1c0c7e3dc046 100644 (file)
--- a/include/clang/Driver/CC1Options.td
+++ b/include/clang/Driver/CC1Options.td
@@ -166,6 +166,8 @@ def mdebug_pass : Separate<"-mdebug-pass">,
   HelpText<"Enable additional debug output">;
 def mdisable_fp_elim : Flag<"-mdisable-fp-elim">,
   HelpText<"Disable frame pointer elimination optimization">;
+def mdisable_tail_calls : Flag<"-mdisable-tail-calls">,
+  HelpText<"Disable tail call optimization, keeping the call stack accurate">;
 def menable_no_infinities : Flag<"-menable-no-infs">,
   HelpText<"Allow optimization to assume there are no infinities.">;
 def menable_no_nans : Flag<"-menable-no-nans">,

diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index 66d7f557fcd73f930cd01ab964d6de636a26b519..18e77770f8aea54941514121e8dedf3e5d8c561d 100644 (file)
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -473,6 +473,8 @@ def fobjc_sender_dependent_dispatch : Flag<"-fobjc-sender-dependent-dispatch">,
 def fobjc : Flag<"-fobjc">, Group<f_Group>;
 def fomit_frame_pointer : Flag<"-fomit-frame-pointer">, Group<f_Group>;
 def fopenmp : Flag<"-fopenmp">, Group<f_Group>;
+def fno_optimize_sibling_calls : Flag<"-fno-optimize-sibling-calls">, Group<f_Group>;
+def foptimize_sibling_calls : Flag<"-foptimize-sibling-calls">, Group<f_Group>;
 def force__cpusubtype__ALL : Flag<"-force_cpusubtype_ALL">;
 def force__flat__namespace : Flag<"-force_flat_namespace">;
 def force__load : Separate<"-force_load">;

diff --git a/include/clang/Frontend/CodeGenOptions.h b/include/clang/Frontend/CodeGenOptions.h
index e6462c0844d77740aacf37b7ec499d332233b440..a0d260fb34f33000af205a1fe4738736da89b368 100644 (file)
--- a/include/clang/Frontend/CodeGenOptions.h
+++ b/include/clang/Frontend/CodeGenOptions.h
@@ -50,6 +50,7 @@ public:
                                   /// internal state before optimizations are
                                   /// done.
   unsigned DisableRedZone    : 1; /// Set when -mno-red-zone is enabled.
+  unsigned DisableTailCalls  : 1; /// Do not emit tail calls.
   unsigned EmitDeclMetadata  : 1; /// Emit special metadata indicating what
                                   /// Decl* various IR entities came from.  Only
                                   /// useful when running CodeGen as a
@@ -166,6 +167,7 @@ public:
     DisableFPElim = 0;
     DisableLLVMOpts = 0;
     DisableRedZone = 0;
+    DisableTailCalls = 0;
     EmitDeclMetadata = 0;
     EmitGcovArcs = 0;
     EmitGcovNotes = 0;

diff --git a/lib/CodeGen/BackendUtil.cpp b/lib/CodeGen/BackendUtil.cpp
index d5350f5031a041b4be144b7d8ea0597c52e5d5cc..c1636952da1fd3abecb3e8718decba8176f2f108 100644 (file)
--- a/lib/CodeGen/BackendUtil.cpp
+++ b/lib/CodeGen/BackendUtil.cpp
@@ -326,6 +326,7 @@ bool EmitAssemblyHelper::AddEmitPasses(BackendAction Action,
   Options.UseSoftFloat = CodeGenOpts.SoftFloat;
   Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
   Options.RealignStack = CodeGenOpts.StackRealignment;
+  Options.DisableTailCalls = CodeGenOpts.DisableTailCalls;
 
   TargetMachine *TM = TheTarget->createTargetMachine(Triple, TargetOpts.CPU,
                                                      FeaturesStr, Options,

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index a3ce05f715deec1758ce3ea3df4c4f2ddcc35812..7254a364df27aa8a870c34c3825e524ed102c21a 100644 (file)
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -1435,6 +1435,9 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                     options::OPT_fno_strict_aliasing,
                     getToolChain().IsStrictAliasingDefault()))
     CmdArgs.push_back("-relaxed-aliasing");
+  if (!Args.hasFlag(options::OPT_foptimize_sibling_calls,
+                    options::OPT_fno_optimize_sibling_calls))
+    CmdArgs.push_back("-mdisable-tail-calls");
 
   // Handle various floating point optimization flags, mapping them to the
   // appropriate LLVM code generation flags. The pattern for all of these is to

diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 671cfc5a05f75713221d7d0cac232baa0a01b6c0..f4576093d8cc1193bcc1ca8db3d61e436c886792 100644 (file)
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -146,6 +146,8 @@ static void CodeGenOptsToArgs(const CodeGenOptions &Opts,
     Res.push_back("-disable-llvm-optzns");
   if (Opts.DisableRedZone)
     Res.push_back("-disable-red-zone");
+  if (Opts.DisableTailCalls)
+    Res.push_back("-mdisable-tail-calls");
   if (!Opts.DebugCompilationDir.empty()) {
     Res.push_back("-fdebug-compilation-dir");
     Res.push_back(Opts.DebugCompilationDir);
@@ -1098,6 +1100,7 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.CodeModel = Args.getLastArgValue(OPT_mcode_model);
   Opts.DebugPass = Args.getLastArgValue(OPT_mdebug_pass);
   Opts.DisableFPElim = Args.hasArg(OPT_mdisable_fp_elim);
+  Opts.DisableTailCalls = Args.hasArg(OPT_mdisable_tail_calls);
   Opts.FloatABI = Args.getLastArgValue(OPT_mfloat_abi);
   Opts.HiddenWeakVTables = Args.hasArg(OPT_fhidden_weak_vtables);
   Opts.LessPreciseFPMAD = Args.hasArg(OPT_cl_mad_enable);

diff --git a/test/Driver/no-sibling-calls.c b/test/Driver/no-sibling-calls.c
new file mode 100644 (file)
index 0000000..c248990
--- /dev/null
+++ b/test/Driver/no-sibling-calls.c
@@ -0,0 +1,8 @@
+// RUN: %clang -### %s -fno-optimize-sibling-calls 2> %t
+// RUN: FileCheck --check-prefix=CHECK-NOSC < %t %s
+// CHECK-NOSC: "-mdisable-tail-calls"
+
+// RUN: %clang -### -foptimize-sibling-calls %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-OSC < %t %s
+// CHECK-OSC-NOT: "-mdisable-tail-calls"
+