diff --git a/clang/lib/AST/PrintfFormatString.cpp b/clang/lib/AST/PrintfFormatString.cpp
index df0a664..a1207aa 100644
--- a/clang/lib/AST/PrintfFormatString.cpp
+++ b/clang/lib/AST/PrintfFormatString.cpp
@@ -315,7 +315,11 @@
     case 'f': k = ConversionSpecifier::fArg; break;
     case 'g': k = ConversionSpecifier::gArg; break;
     case 'i': k = ConversionSpecifier::iArg; break;
-    case 'n': k = ConversionSpecifier::nArg; break;
+    case 'n':
+      // Not handled, but reserved in OpenCL.
+      if (!LO.OpenCL)
+        k = ConversionSpecifier::nArg;
+      break;
     case 'o': k = ConversionSpecifier::oArg; break;
     case 'p': k = ConversionSpecifier::pArg; break;
     case 's': k = ConversionSpecifier::sArg; break;
@@ -486,10 +490,12 @@
         // GNU extension.
         return Ctx.LongLongTy;
       case LengthModifier::None:
+      case LengthModifier::AsShortLong:
         return Ctx.IntTy;
       case LengthModifier::AsInt32:
         return ArgType(Ctx.IntTy, "__int32");
-      case LengthModifier::AsChar: return ArgType::AnyCharTy;
+      case LengthModifier::AsChar:
+        return ArgType::AnyCharTy;
       case LengthModifier::AsShort: return Ctx.ShortTy;
       case LengthModifier::AsLong: return Ctx.LongTy;
       case LengthModifier::AsLongLong:
@@ -520,6 +526,7 @@
         // GNU extension.
         return Ctx.UnsignedLongLongTy;
       case LengthModifier::None:
+      case LengthModifier::AsShortLong:
         return Ctx.UnsignedIntTy;
       case LengthModifier::AsInt32:
         return ArgType(Ctx.UnsignedIntTy, "unsigned __int32");
@@ -549,6 +556,18 @@
     }
 
   if (CS.isDoubleArg()) {
+    if (!VectorNumElts.isInvalid()) {
+      switch (LM.getKind()) {
+      case LengthModifier::AsShort:
+        return Ctx.HalfTy;
+      case LengthModifier::AsShortLong:
+        return Ctx.FloatTy;
+      case LengthModifier::AsLong:
+      default:
+        return Ctx.DoubleTy;
+      }
+    }
+
     if (LM.getKind() == LengthModifier::AsLongDouble)
       return Ctx.LongDoubleTy;
     return Ctx.DoubleTy;
@@ -582,6 +601,8 @@
       case LengthModifier::AsInt64:
       case LengthModifier::AsWide:
         return ArgType::Invalid();
+      case LengthModifier::AsShortLong:
+        llvm_unreachable("only used for OpenCL which doesn not handle nArg");
     }
   }
 
@@ -760,10 +781,13 @@
   case BuiltinType::UInt:
   case BuiltinType::Int:
   case BuiltinType::Float:
-  case BuiltinType::Double:
-    LM.setKind(LengthModifier::None);
+    LM.setKind(VectorNumElts.isInvalid() ?
+               LengthModifier::None : LengthModifier::AsShortLong);
     break;
-
+  case BuiltinType::Double:
+    LM.setKind(VectorNumElts.isInvalid() ?
+               LengthModifier::None : LengthModifier::AsLong);
+    break;
   case BuiltinType::Char_U:
   case BuiltinType::UChar:
   case BuiltinType::Char_S:
@@ -796,7 +820,7 @@
     namedTypeToLengthModifier(QT, LM);
 
   // If fixing the length modifier was enough, we might be done.
-  if (hasValidLengthModifier(Ctx.getTargetInfo())) {
+  if (hasValidLengthModifier(Ctx.getTargetInfo(), LangOpt)) {
     // If we're going to offer a fix anyway, make sure the sign matches.
     switch (CS.getKind()) {
     case ConversionSpecifier::uArg: