[X86][PowerPC] Support -mlong-double-128

This patch makes the driver option -mlong-double-128 available for X86
and PowerPC. The CC1 option -mlong-double-128 is available on all targets
for users to test on unsupported targets.

On PowerPC, -mlong-double-128 uses the IBM extended double format
because we don't support -mabi=ieeelongdouble yet (D64283).

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D64277

llvm-svn: 365866

2 files changed, 6 insertions, 2 deletions

diff --git a/clang/lib/Basic/Targets/PPC.cpp b/clang/lib/Basic/Targets/PPC.cpp
index b052ef433ec..bd0ae600380 100644
--- a/clang/lib/Basic/Targets/PPC.cpp
+++ b/clang/lib/Basic/Targets/PPC.cpp
@@ -465,6 +465,8 @@ void PPCTargetInfo::adjust(LangOptions &Opts) {
   if (HasAltivec)
     Opts.AltiVec = 1;
   TargetInfo::adjust(Opts);
+  if (LongDoubleFormat != &llvm::APFloat::IEEEdouble())
+    LongDoubleFormat = &llvm::APFloat::PPCDoubleDouble();
 }
 
 ArrayRef<Builtin::Info> PPCTargetInfo::getTargetBuiltins() const {
diff --git a/clang/lib/Basic/Targets/X86.h b/clang/lib/Basic/Targets/X86.h
index c0dfc81f57c..588b6d3da1d 100644
--- a/clang/lib/Basic/Targets/X86.h
+++ b/clang/lib/Basic/Targets/X86.h
@@ -133,6 +133,10 @@ public:
     LongDoubleFormat = &llvm::APFloat::x87DoubleExtended();
   }
 
+  const char *getLongDoubleMangling() const override {
+    return LongDoubleFormat == &llvm::APFloat::IEEEquad() ? "g" : "e";
+  }
+
   unsigned getFloatEvalMethod() const override {
     // X87 evaluates with 80 bits "long double" precision.
     return SSELevel == NoSSE ? 2 : 0;
@@ -845,8 +849,6 @@ public:
       : LinuxTargetInfo<X86_64TargetInfo>(Triple, Opts) {
     LongDoubleFormat = &llvm::APFloat::IEEEquad();
   }
-
-  const char *getLongDoubleMangling() const override { return "g"; }
 };
 } // namespace targets
 } // namespace clang