Index: lib/CodeGen/TargetInfo.cpp
===================================================================
--- lib/CodeGen/TargetInfo.cpp
+++ lib/CodeGen/TargetInfo.cpp
@@ -882,8 +882,14 @@
 /// X86_VectorCall calling convention. Shared between x86_32 and x86_64.
 static bool isX86VectorTypeForVectorCall(ASTContext &Context, QualType Ty) {
   if (const BuiltinType *BT = Ty->getAs<BuiltinType>()) {
-    if (BT->isFloatingPoint() && BT->getKind() != BuiltinType::Half)
+    if (BT->isFloatingPoint() && BT->getKind() != BuiltinType::Half) {
+      if (BT->getKind() == BuiltinType::LongDouble) {
+        if (&Context.getTargetInfo().getLongDoubleFormat() ==
+            &llvm::APFloat::x87DoubleExtended())
+          return false;
+      }
       return true;
+    }
   } else if (const VectorType *VT = Ty->getAs<VectorType>()) {
     // vectorcall can pass XMM, YMM, and ZMM vectors. We don't pass SSE1 MMX
     // registers specially.
@@ -3505,6 +3511,8 @@
   unsigned FreeSSERegs = IsRegCall ? 16 : 8;
   unsigned NeededInt, NeededSSE;
 
+  // Complex Long Double Type is passed in Memory when Regcall
+  // calling convention is used.
   if (IsRegCall && FI.getReturnType()->getTypePtr()->isRecordType() &&
       !FI.getReturnType()->getTypePtr()->isUnionType()) {
     FI.getReturnInfo() =
@@ -3515,6 +3523,11 @@
     } else {
       FI.getReturnInfo() = getIndirectReturnResult(FI.getReturnType());
     }
+  } else if (IsRegCall && FI.getReturnType()->getAs<ComplexType>()) {
+    const ComplexType *CT = FI.getReturnType()->getAs<ComplexType>();
+    if (getContext().getCanonicalType(CT->getElementType()) ==
+        getContext().LongDoubleTy)
+      FI.getReturnInfo() = getIndirectReturnResult(FI.getReturnType());
   } else if (!getCXXABI().classifyReturnType(FI))
     FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
 
Index: test/CodeGenCXX/regcall.cpp
===================================================================
--- test/CodeGenCXX/regcall.cpp
+++ test/CodeGenCXX/regcall.cpp
@@ -95,3 +95,11 @@
   freeTempFunc(1);
   t3.do_thing();
 }
+
+long double _Complex __regcall foo(long double _Complex f) {
+  return f;
+}
+// CHECK-LIN64-DAG: define x86_regcallcc void @_Z15__regcall3__fooCe({ x86_fp80, x86_fp80 }* noalias sret %agg.result, { x86_fp80, x86_fp80 }* byval align 16 %f)
+// CHECK-LIN32-DAG: define x86_regcallcc void @_Z15__regcall3__fooCe({ x86_fp80, x86_fp80 }* inreg noalias sret %agg.result, { x86_fp80, x86_fp80 }* byval align 4 %f)
+// CHECK-WIN64-DAG: define x86_regcallcc { double, double } @"\01?foo@@YwU?$_Complex@O@__clang@@U12@@Z"(double %f.0, double %f.1)
+// CHECK-WIN32-DAG: define x86_regcallcc { double, double } @"\01?foo@@YwU?$_Complex@O@__clang@@U12@@Z"(double %f.0, double %f.1)