diff --git a/include/llvm/Analysis/DebugInfo.h b/include/llvm/Analysis/DebugInfo.h
index 4189f5d9b84..8b4a4c184e8 100644
--- a/include/llvm/Analysis/DebugInfo.h
+++ b/include/llvm/Analysis/DebugInfo.h
@@ -119,6 +119,7 @@ namespace llvm {
     bool isEnumerator() const;
     bool isType() const;
     bool isGlobal() const;
+    bool isUnspecifiedParameter() const;
   };
 
   /// DISubrange - This is used to represent ranges, for array bounds.
@@ -626,6 +627,10 @@ namespace llvm {
     /// implicitly uniques the values returned.
     DISubrange GetOrCreateSubrange(int64_t Lo, int64_t Hi);
 
+    /// CreateUnspecifiedParameter - Create unspeicified type descriptor
+    /// for a subroutine type.
+    DIDescriptor CreateUnspecifiedParameter();
+
     /// CreateCompileUnit - Create a new descriptor for the specified compile
     /// unit.
     DICompileUnit CreateCompileUnit(unsigned LangID,
diff --git a/lib/Analysis/DebugInfo.cpp b/lib/Analysis/DebugInfo.cpp
index 06a66d5539e..3dd659833e0 100644
--- a/lib/Analysis/DebugInfo.cpp
+++ b/lib/Analysis/DebugInfo.cpp
@@ -199,6 +199,12 @@ bool DIDescriptor::isGlobal() const {
   return isGlobalVariable();
 }
 
+/// isUnspecifiedParmeter - Return true if the specified tab is
+/// DW_TAG_unspecified_parameters.
+bool DIDescriptor::isUnspecifiedParameter() const {
+  return DbgNode && getTag() == dwarf::DW_TAG_unspecified_parameters;
+}
+
 /// isScope - Return true if the specified tag is one of the scope
 /// related tag.
 bool DIDescriptor::isScope() const {
@@ -724,7 +730,14 @@ DISubrange DIFactory::GetOrCreateSubrange(int64_t Lo, int64_t Hi) {
   return DISubrange(MDNode::get(VMContext, &Elts[0], 3));
 }
 
-
+/// CreateUnspecifiedParameter - Create unspeicified type descriptor
+/// for the subroutine type.
+DIDescriptor DIFactory::CreateUnspecifiedParameter() {
+  Value *Elts[] = {
+    GetTagConstant(dwarf::DW_TAG_unspecified_parameters)
+  };
+  return DIDescriptor(MDNode::get(VMContext, &Elts[0], 1));
+}
 
 /// CreateCompileUnit - Create a new descriptor for the specified compile
 /// unit.  Note that this does not unique compile units within the module.
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index ddda1844070..b2ae1a24c11 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1042,16 +1042,25 @@ void DwarfDebug::constructTypeDIE(DIE &Buffer, DICompositeType CTy) {
     DIDescriptor RTy = Elements.getElement(0);
     addType(&Buffer, DIType(RTy));
 
-    // Add prototype flag.
-    addUInt(&Buffer, dwarf::DW_AT_prototyped, dwarf::DW_FORM_flag, 1);
-
+    bool isPrototyped = true;
     // Add arguments.
     for (unsigned i = 1, N = Elements.getNumElements(); i < N; ++i) {
-      DIE *Arg = new DIE(dwarf::DW_TAG_formal_parameter);
       DIDescriptor Ty = Elements.getElement(i);
-      addType(Arg, DIType(Ty));
-      Buffer.addChild(Arg);
+      if (Ty.isUnspecifiedParameter()) {
+        DIE *Arg = new DIE(dwarf::DW_TAG_unspecified_parameters);
+        Buffer.addChild(Arg);
+        isPrototyped = false;
+      } else {
+        DIE *Arg = new DIE(dwarf::DW_TAG_formal_parameter);
+        addType(Arg, DIType(Ty));
+        Buffer.addChild(Arg);
+      }
     }
+    // Add prototype flag.
+    if (isPrototyped)
+      addUInt(&Buffer, dwarf::DW_AT_prototyped, dwarf::DW_FORM_flag, 1);
+
+
   }
     break;
   case dwarf::DW_TAG_structure_type: