[X86] Support -mlong-double-80

Add an option group for all of the -mlong-double-* options and make
-mlong-double-80 restore the default long double behavior for X86.  The
motivations are that GNU accepts the -mlong-double-80 option and that complex
Makefiles often need a way of undoing earlier options. Prior to this commit, if
one chooses 64-bit or 128-bit long double for X86, there is no way to undo that
choice and restore the 80-bit behavior.

Differential Revision: https://reviews.llvm.org/D66055

llvm-svn: 369183

1 files changed, 5 insertions, 4 deletions

diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 2e9ccca4b29..690d4fa3fa4 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -4057,11 +4057,12 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
 
   RenderFloatingPointOptions(TC, D, OFastEnabled, Args, CmdArgs);
 
-  if (Arg *A = Args.getLastArg(options::OPT_mlong_double_64,
-                               options::OPT_mlong_double_128)) {
+  if (Arg *A = Args.getLastArg(options::OPT_LongDouble_Group)) {
     if (TC.getArch() == llvm::Triple::x86 ||
-        TC.getArch() == llvm::Triple::x86_64 ||
-        TC.getArch() == llvm::Triple::ppc || TC.getTriple().isPPC64())
+        TC.getArch() == llvm::Triple::x86_64)
+      A->render(Args, CmdArgs);
+    else if ((TC.getArch() == llvm::Triple::ppc || TC.getTriple().isPPC64()) &&
+             (A->getOption().getID() != options::OPT_mlong_double_80))
       A->render(Args, CmdArgs);
     else
       D.Diag(diag::err_drv_unsupported_opt_for_target)