1 files changed, 7 insertions, 1 deletions
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index e4db004b4948a..9e44f7d9be631 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -3968,7 +3968,13 @@ public:
 class MinGWX86_64TargetInfo : public WindowsX86_64TargetInfo {
 public:
   MinGWX86_64TargetInfo(const llvm::Triple &Triple)
-      : WindowsX86_64TargetInfo(Triple) {}
+      : WindowsX86_64TargetInfo(Triple) {
+    // Mingw64 rounds long double size and alignment up to 16 bytes, but sticks
+    // with x86 FP ops. Weird.
+    LongDoubleWidth = LongDoubleAlign = 128;
+    LongDoubleFormat = &llvm::APFloat::x87DoubleExtended;
+  }
+
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override {
     WindowsX86_64TargetInfo::getTargetDefines(Opts, Builder);