[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

1 files changed, 9 insertions, 4 deletions

diff --git a/clang/lib/Basic/TargetInfo.cpp b/clang/lib/Basic/TargetInfo.cpp
index 43ab77289b1..a9dfe69b90c 100644
--- a/clang/lib/Basic/TargetInfo.cpp
+++ b/clang/lib/Basic/TargetInfo.cpp
@@ -373,10 +373,15 @@ void TargetInfo::adjust(LangOptions &Opts) {
     LongDoubleFormat = &llvm::APFloat::IEEEquad();
   }
 
-  if (Opts.LongDoubleSize && Opts.LongDoubleSize == DoubleWidth) {
-    LongDoubleWidth = DoubleWidth;
-    LongDoubleAlign = DoubleAlign;
-    LongDoubleFormat = DoubleFormat;
+  if (Opts.LongDoubleSize) {
+    if (Opts.LongDoubleSize == DoubleWidth) {
+      LongDoubleWidth = DoubleWidth;
+      LongDoubleAlign = DoubleAlign;
+      LongDoubleFormat = DoubleFormat;
+    } else if (Opts.LongDoubleSize == 128) {
+      LongDoubleWidth = LongDoubleAlign = 128;
+      LongDoubleFormat = &llvm::APFloat::IEEEquad();
+    }
   }
 
   if (Opts.NewAlignOverride)