Driver: Add support for -m[no-]relax-all, and make it the default at -O0.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@104815 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 21 insertions, 0 deletions

diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index abab2ddd65..a9a52c01f4 100644
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -139,6 +139,7 @@ def MQ : JoinedOrSeparate<"-MQ">, Group<M_Group>;
 def MT : JoinedOrSeparate<"-MT">, Group<M_Group>;
 def Mach : Flag<"-Mach">;
 def M : Flag<"-M">, Group<M_Group>;
+def O0 : Joined<"-O0">, Group<O_Group>;
 def O4 : Joined<"-O4">, Group<O_Group>;
 def ObjCXX : Flag<"-ObjC++">, Flags<[DriverOption]>,
   HelpText<"Treat source input files as Objective-C++ inputs">;
@@ -436,6 +437,7 @@ def mno_constant_cfstrings : Flag<"-mno-constant-cfstrings">, Group<m_Group>;
 def mno_mmx : Flag<"-mno-mmx">, Group<m_x86_Features_Group>;
 def mno_pascal_strings : Flag<"-mno-pascal-strings">, Group<m_Group>;
 def mno_red_zone : Flag<"-mno-red-zone">, Group<m_Group>;
+def mno_relax_all : Flag<"-mno-relax-all">, Group<m_Group>;
 def mno_soft_float : Flag<"-mno-soft-float">, Group<m_Group>;
 def mno_sse2 : Flag<"-mno-sse2">, Group<m_x86_Features_Group>;
 def mno_sse3 : Flag<"-mno-sse3">, Group<m_x86_Features_Group>;
@@ -453,6 +455,7 @@ def marm : Flag<"-marm">, Alias<mno_thumb>;
 def mno_warn_nonportable_cfstrings : Flag<"-mno-warn-nonportable-cfstrings">, Group<m_Group>;
 def mpascal_strings : Flag<"-mpascal-strings">, Group<m_Group>;
 def mred_zone : Flag<"-mred-zone">, Group<m_Group>;
+def mrelax_all : Flag<"-mrelax-all">, Group<m_Group>;
 def msoft_float : Flag<"-msoft-float">, Group<m_Group>;
 def msse2 : Flag<"-msse2">, Group<m_x86_Features_Group>;
 def msse3 : Flag<"-msse3">, Group<m_x86_Features_Group>;
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 896811d5d3..ab00f96a83 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -768,6 +768,15 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
       CmdArgs.push_back("-E");
   } else if (isa<AssembleJobAction>(JA)) {
     CmdArgs.push_back("-emit-obj");
+
+    // At -O0, we use -mrelax-all by default.
+    bool IsOpt = false;
+    if (Arg *A = Args.getLastArg(options::OPT_O_Group))
+      IsOpt = !A->getOption().matches(options::OPT_O0);
+    if (Args.hasFlag(options::OPT_mrelax_all,
+                      options::OPT_mno_relax_all,
+                      !IsOpt))
+      CmdArgs.push_back("-mrelax-all");
   } else if (isa<PrecompileJobAction>(JA)) {
     // Use PCH if the user requested it, except for C++ (for now).
     bool UsePCH = D.CCCUsePCH;
@@ -1512,6 +1521,15 @@ void ClangAs::ConstructJob(Compilation &C, const JobAction &JA,
   CmdArgs.push_back("-filetype");
   CmdArgs.push_back("obj");
 
+  // At -O0, we use -mrelax-all by default.
+  bool IsOpt = false;
+  if (Arg *A = Args.getLastArg(options::OPT_O_Group))
+    IsOpt = !A->getOption().matches(options::OPT_O0);
+  if (Args.hasFlag(options::OPT_mrelax_all,
+                    options::OPT_mno_relax_all,
+                    !IsOpt))
+    CmdArgs.push_back("-mrelax-all");
+
   // FIXME: Add -force_cpusubtype_ALL support, once we have it.
 
   // FIXME: Add -g support, once we have it.