diff --git a/llvm/include/llvm/Analysis/DebugInfo.h b/llvm/include/llvm/Analysis/DebugInfo.h
index 489c273ed4a9..01c1decb83d2 100644
--- a/llvm/include/llvm/Analysis/DebugInfo.h
+++ b/llvm/include/llvm/Analysis/DebugInfo.h
@@ -87,6 +87,13 @@ namespace llvm {
 
     /// dump - print descriptor.
     void dump() const;
+
+    bool isDerivedType() const;
+    bool isCompositeType() const;
+    bool isBasicType() const;
+    bool isVariable() const;
+    bool isSubprogram() const;
+    bool isGlobalVariable() const;
   };
 
   /// DISubrange - This is used to represent ranges, for array bounds.
@@ -185,19 +192,6 @@ namespace llvm {
     DIType(MDNode *N, bool, bool) : DIDescriptor(N) {}
 
   public:
-    /// isDerivedType - Return true if the specified tag is legal for
-    /// DIDerivedType.
-    static bool isDerivedType(unsigned TAG);
-
-    /// isCompositeType - Return true if the specified tag is legal for
-    /// DICompositeType.
-    static bool isCompositeType(unsigned TAG);
-
-    /// isBasicType - Return true if the specified tag is legal for
-    /// DIBasicType.
-    static bool isBasicType(unsigned TAG) {
-      return TAG == dwarf::DW_TAG_base_type;
-    }
 
     /// Verify - Verify that a type descriptor is well formed.
     bool Verify() const;
@@ -257,7 +251,7 @@ namespace llvm {
   public:
     explicit DIDerivedType(MDNode *N = 0)
       : DIType(N, true, true) {
-      if (DbgNode && !isDerivedType(getTag()))
+      if (DbgNode && !isDerivedType())
         DbgNode = 0;
     }
 
@@ -282,7 +276,7 @@ namespace llvm {
   public:
     explicit DICompositeType(MDNode *N = 0)
       : DIDerivedType(N, true, true) {
-      if (N && !isCompositeType(getTag()))
+      if (N && !isCompositeType())
         DbgNode = 0;
     }
 
@@ -302,18 +296,6 @@ namespace llvm {
     explicit DIGlobal(MDNode *N, unsigned RequiredTag)
       : DIDescriptor(N, RequiredTag) {}
 
-    /// isSubprogram - Return true if the specified tag is legal for
-    /// DISubprogram.
-    static bool isSubprogram(unsigned TAG) {
-      return TAG == dwarf::DW_TAG_subprogram;
-    }
-
-    /// isGlobalVariable - Return true if the specified tag is legal for
-    /// DIGlobalVariable.
-    static bool isGlobalVariable(unsigned TAG) {
-      return TAG == dwarf::DW_TAG_variable;
-    }
-
   public:
     virtual ~DIGlobal() {}
 
@@ -393,7 +375,7 @@ namespace llvm {
   public:
     explicit DIVariable(MDNode *N = 0)
       : DIDescriptor(N) {
-      if (DbgNode && !isVariable(getTag()))
+      if (DbgNode && !isVariable())
         DbgNode = 0;
     }
 
@@ -405,8 +387,6 @@ namespace llvm {
     unsigned getLineNumber() const      { return getUnsignedField(4); }
     DIType getType() const              { return getFieldAs<DIType>(5); }
 
-    /// isVariable - Return true if the specified tag is legal for DIVariable.
-    static bool isVariable(unsigned Tag);
 
     /// Verify - Verify that a variable descriptor is well formed.
     bool Verify() const;
diff --git a/llvm/lib/Analysis/DebugInfo.cpp b/llvm/lib/Analysis/DebugInfo.cpp
index 0d4b213e8061..69018894c632 100644
--- a/llvm/lib/Analysis/DebugInfo.cpp
+++ b/llvm/lib/Analysis/DebugInfo.cpp
@@ -124,22 +124,23 @@ GlobalVariable *DIDescriptor::getGlobalVariableField(unsigned Elt) const {
 }
 
 //===----------------------------------------------------------------------===//
-// Simple Descriptor Constructors and other Methods
+// Predicates
 //===----------------------------------------------------------------------===//
 
-// Needed by DIVariable::getType().
-DIType::DIType(MDNode *N) : DIDescriptor(N) {
-  if (!N) return;
-  unsigned tag = getTag();
-  if (tag != dwarf::DW_TAG_base_type && !DIDerivedType::isDerivedType(tag) &&
-      !DICompositeType::isCompositeType(tag)) {
-    DbgNode = 0;
-  }
+/// isBasicType - Return true if the specified tag is legal for
+/// DIBasicType.
+bool DIDescriptor::isBasicType() const {
+  assert (isNull() && "Invalid descriptor!");
+  unsigned Tag = getTag();
+  
+  return Tag == dwarf::DW_TAG_base_type;
 }
 
-/// isDerivedType - Return true if the specified tag is legal for
-/// DIDerivedType.
-bool DIType::isDerivedType(unsigned Tag) {
+/// isDerivedType - Return true if the specified tag is legal for DIDerivedType.
+bool DIDescriptor::isDerivedType() const {
+  assert (isNull() && "Invalid descriptor!");
+  unsigned Tag = getTag();
+
   switch (Tag) {
   case dwarf::DW_TAG_typedef:
   case dwarf::DW_TAG_pointer_type:
@@ -152,14 +153,17 @@ bool DIType::isDerivedType(unsigned Tag) {
     return true;
   default:
     // CompositeTypes are currently modelled as DerivedTypes.
-    return isCompositeType(Tag);
+    return isCompositeType();
   }
 }
 
 /// isCompositeType - Return true if the specified tag is legal for
 /// DICompositeType.
-bool DIType::isCompositeType(unsigned TAG) {
-  switch (TAG) {
+bool DIDescriptor::isCompositeType() const {
+  assert (isNull() && "Invalid descriptor!");
+  unsigned Tag = getTag();
+
+  switch (Tag) {
   case dwarf::DW_TAG_array_type:
   case dwarf::DW_TAG_structure_type:
   case dwarf::DW_TAG_union_type:
@@ -174,7 +178,10 @@ bool DIType::isCompositeType(unsigned TAG) {
 }
 
 /// isVariable - Return true if the specified tag is legal for DIVariable.
-bool DIVariable::isVariable(unsigned Tag) {
+bool DIDescriptor::isVariable() const {
+  assert (isNull() && "Invalid descriptor!");
+  unsigned Tag = getTag();
+
   switch (Tag) {
   case dwarf::DW_TAG_auto_variable:
   case dwarf::DW_TAG_arg_variable:
@@ -185,6 +192,36 @@ bool DIVariable::isVariable(unsigned Tag) {
   }
 }
 
+/// isSubprogram - Return true if the specified tag is legal for
+/// DISubprogram.
+bool DIDescriptor::isSubprogram() const {
+  assert (isNull() && "Invalid descriptor!");
+  unsigned Tag = getTag();
+  
+  return Tag == dwarf::DW_TAG_subprogram;
+}
+
+/// isGlobalVariable - Return true if the specified tag is legal for
+/// DIGlobalVariable.
+bool DIDescriptor::isGlobalVariable() const {
+  assert (isNull() && "Invalid descriptor!");
+  unsigned Tag = getTag();
+
+  return Tag == dwarf::DW_TAG_variable;
+}
+
+
+//===----------------------------------------------------------------------===//
+// Simple Descriptor Constructors and other Methods
+//===----------------------------------------------------------------------===//
+
+DIType::DIType(MDNode *N) : DIDescriptor(N) {
+  if (!N) return;
+  if (!isBasicType() && !isDerivedType() && !isCompositeType()) {
+    DbgNode = 0;
+  }
+}
+
 unsigned DIArray::getNumElements() const {
   assert (DbgNode && "Invalid DIArray");
   return DbgNode->getNumElements();
@@ -366,11 +403,11 @@ void DIType::dump() const {
   if (isForwardDecl())
     errs() << " [fwd] ";
 
-  if (isBasicType(Tag))
+  if (isBasicType())
     DIBasicType(DbgNode).dump();
-  else if (isDerivedType(Tag))
+  else if (isDerivedType())
     DIDerivedType(DbgNode).dump();
-  else if (isCompositeType(Tag))
+  else if (isCompositeType())
     DICompositeType(DbgNode).dump();
   else {
     errs() << "Invalid DIType\n";
@@ -417,7 +454,7 @@ void DIGlobal::dump() const {
   if (isDefinition())
     errs() << " [def] ";
 
-  if (isGlobalVariable(Tag))
+  if (isGlobalVariable())
     DIGlobalVariable(DbgNode).dump();
 
   errs() << "\n";
@@ -818,7 +855,7 @@ void DebugInfoFinder::processType(DIType DT) {
     return;
 
   addCompileUnit(DT.getCompileUnit());
-  if (DT.isCompositeType(DT.getTag())) {
+  if (DT.isCompositeType()) {
     DICompositeType DCT(DT.getNode());
     processType(DCT.getTypeDerivedFrom());
     DIArray DA = DCT.getTypeArray();
@@ -831,7 +868,7 @@ void DebugInfoFinder::processType(DIType DT) {
         else 
           processSubprogram(DISubprogram(D.getNode()));
       }
-  } else if (DT.isDerivedType(DT.getTag())) {
+  } else if (DT.isDerivedType()) {
     DIDerivedType DDT(DT.getNode());
     if (!DDT.isNull()) 
       processType(DDT.getTypeDerivedFrom());
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index efa7577c6272..0e8521e83e59 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -547,12 +547,12 @@ void DwarfDebug::AddType(CompileUnit *DW_Unit, DIE *Entity, DIType Ty) {
 
   // Construct type.
   DIE Buffer(dwarf::DW_TAG_base_type);
-  if (Ty.isBasicType(Ty.getTag()))
+  if (Ty.isBasicType())
     ConstructTypeDIE(DW_Unit, Buffer, DIBasicType(Ty.getNode()));
-  else if (Ty.isCompositeType(Ty.getTag()))
+  else if (Ty.isCompositeType())
     ConstructTypeDIE(DW_Unit, Buffer, DICompositeType(Ty.getNode()));
   else {
-    assert(Ty.isDerivedType(Ty.getTag()) && "Unknown kind of DIType");
+    assert(Ty.isDerivedType() && "Unknown kind of DIType");
     ConstructTypeDIE(DW_Unit, Buffer, DIDerivedType(Ty.getNode()));
 
   }
diff --git a/llvm/lib/Target/PIC16/PIC16DebugInfo.cpp b/llvm/lib/Target/PIC16/PIC16DebugInfo.cpp
index 4dcd84dc57e3..3499e5c35604 100644
--- a/llvm/lib/Target/PIC16/PIC16DebugInfo.cpp
+++ b/llvm/lib/Target/PIC16/PIC16DebugInfo.cpp
@@ -28,11 +28,11 @@ using namespace llvm;
 void PIC16DbgInfo::PopulateDebugInfo (DIType Ty, unsigned short &TypeNo,
                                       bool &HasAux, int Aux[], 
                                       std::string &TagName) {
-  if (Ty.isBasicType(Ty.getTag())) 
+  if (Ty.isBasicType())
     PopulateBasicTypeInfo (Ty, TypeNo);
-  else if (Ty.isDerivedType(Ty.getTag())) 
+  else if (Ty.isDerivedType())
     PopulateDerivedTypeInfo (Ty, TypeNo, HasAux, Aux, TagName);
-  else if (Ty.isCompositeType(Ty.getTag())) 
+  else if (Ty.isCompositeType())
     PopulateCompositeTypeInfo (Ty, TypeNo, HasAux, Aux, TagName);
   else {
     TypeNo = PIC16Dbg::T_NULL;