Index: lib/Sema/SemaExpr.cpp
===================================================================
--- lib/Sema/SemaExpr.cpp
+++ lib/Sema/SemaExpr.cpp
@@ -5709,7 +5709,7 @@
       RHS.get()->getType()->isVectorType())
     return CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false);
 
-  UsualArithmeticConversions(LHS, RHS);
+  QualType ResTy = UsualArithmeticConversions(LHS, RHS);
   if (LHS.isInvalid() || RHS.isInvalid())
     return QualType();
 
@@ -5726,8 +5726,12 @@
   
   // If both operands have arithmetic type, do the usual arithmetic conversions
   // to find a common type: C99 6.5.15p3,5.
-  if (LHSTy->isArithmeticType() && RHSTy->isArithmeticType())
-    return LHS.get()->getType();
+  if (LHSTy->isArithmeticType() && RHSTy->isArithmeticType()) {
+    LHS = ImpCastExprToType(LHS.get(), ResTy, PrepareScalarCast(LHS, ResTy));
+    RHS = ImpCastExprToType(RHS.get(), ResTy, PrepareScalarCast(RHS, ResTy));
+
+    return ResTy;
+  }
 
   // If both operands are the same structure or union type, the result is that
   // type.
Index: lib/Sema/SemaExprCXX.cpp
===================================================================
--- lib/Sema/SemaExprCXX.cpp
+++ lib/Sema/SemaExprCXX.cpp
@@ -4561,10 +4561,14 @@
   //      the usual arithmetic conversions are performed to bring them to a
   //      common type, and the result is of that type.
   if (LTy->isArithmeticType() && RTy->isArithmeticType()) {
-    UsualArithmeticConversions(LHS, RHS);
+    QualType ResTy = UsualArithmeticConversions(LHS, RHS);
     if (LHS.isInvalid() || RHS.isInvalid())
       return QualType();
-    return LHS.get()->getType();
+
+    LHS = ImpCastExprToType(LHS.get(), ResTy, PrepareScalarCast(LHS, ResTy));
+    RHS = ImpCastExprToType(RHS.get(), ResTy, PrepareScalarCast(RHS, ResTy));
+
+    return ResTy;
   }
 
   //   -- The second and third operands have pointer type, or one has pointer
Index: test/CodeGen/complex.c
===================================================================
--- test/CodeGen/complex.c
+++ test/CodeGen/complex.c
@@ -98,3 +98,12 @@
 
 const _Complex double test9const = 0;
 _Complex double test9func() { return test9const; }
+
+// D6217
+void t9() {
+  // Check for proper type promotion of conditional expression
+  char c[(int)(sizeof(typeof((0 ? 2.0f : (_Complex double) 2.0f))) - sizeof(_Complex double))];
+  // Check for proper codegen
+  (0 ? 2.0f : (_Complex double) 2.0f);
+}
+