[PATCH] D11437: Correct x86_64 fp128 mangled name and return/varargs types

[David Majnemer]

majnemer added inline comments.

================
Comment at: lib/CodeGen/TargetInfo.cpp:1974-1989
@@ -1973,8 +1973,18 @@
       Current = SSE;
     else if (ET == getContext().DoubleTy ||
              (ET == getContext().LongDoubleTy &&
               getTarget().getTriple().isOSNaCl()))
       Lo = Hi = SSE;
-    else if (ET == getContext().LongDoubleTy)
-      Current = ComplexX87;
+    else if (ET == getContext().LongDoubleTy) {
+      // AMD64 ABI says that long double should be f80 and
+      // complex long double should be ComplexX87.
+      // However, it also defines __float128 as f128 in SSE,
+      // complex float and complex double like structure.
+      // So complex __float128 should be like structure,
+      // which is also implemented by gcc.
+      if (auto ResType = CGT.ConvertType(ET))
+        Current = ResType->isFP128Ty() ? Memory : ComplexX87;
+      else
+        Current = ComplexX87;
+    }
 
----------------
I'd phrase this as:
  } else if (ET == getContext().DoubleTy) {
    Lo = Hi = SSE;
  } else if (ET == getContext().LongDoubleTy) {
    const llvm::fltSemantics *LDF = &getTarget().getLongDoubleFormat();
    if (LDF == &llvm::APFloat::IEEEquad)
      Current = Memory;
    else if (LDF == &llvm::APFloat::x87DoubleExtended)
      Current = ComplexX87;
    else if (LDF == &llvm::APFloat::IEEEdouble)
      Lo = Hi = SSE;
    else
      llvm_unreachable("unexpected long double representation!");
  }


http://reviews.llvm.org/D11437