diff --git a/lib/Bytecode/Reader/ConstantReader.cpp b/lib/Bytecode/Reader/ConstantReader.cpp
index b85bd88..dd47d1c 100644
--- a/lib/Bytecode/Reader/ConstantReader.cpp
+++ b/lib/Bytecode/Reader/ConstantReader.cpp
@@ -156,7 +156,7 @@
       unsigned Slot;
       if (read_vbr(Buf, EndBuf, Slot)) return true;
       Value *V = getValue(AT->getElementType(), Slot, false);
-      if (!V || V->getValueType() != Value::ConstantVal)
+      if (!V || !V->isConstant())
 	return true;
       Elements.push_back((ConstPoolVal*)V);
     }
@@ -173,7 +173,7 @@
       unsigned Slot;
       if (read_vbr(Buf, EndBuf, Slot)) return true;
       Value *V = getValue(ET[i], Slot, false);
-      if (!V || V->getValueType() != Value::ConstantVal)
+      if (!V || !V->isConstant())
 	return true;
       Elements.push_back((ConstPoolVal*)V);      
     }
diff --git a/lib/Bytecode/Reader/Reader.cpp b/lib/Bytecode/Reader/Reader.cpp
index c3f4c90..e8bf17e 100644
--- a/lib/Bytecode/Reader/Reader.cpp
+++ b/lib/Bytecode/Reader/Reader.cpp
@@ -46,11 +46,8 @@
   const Value *D = getValue(Type::TypeTy, ID, false);
   if (D == 0) return 0;
 
-  assert(D->getType() == Type::TypeTy &&
-	 D->getValueType() == Value::ConstantVal);
-
-
-  return ((const ConstPoolType*)D)->getValue();;
+  assert(D->getType() == Type::TypeTy);
+  return ((const ConstPoolType*)D->castConstantAsserting())->getValue();
 }
 
 bool BytecodeParser::insertValue(Value *Def, vector<ValueList> &ValueTab) {
@@ -63,7 +60,7 @@
   //cerr << "insertValue Values[" << type << "][" << ValueTab[type].size() 
   //     << "] = " << Def << endl;
 
-  if (type == Type::TypeTyID && Def->getValueType() == Value::ConstantVal) {
+  if (type == Type::TypeTyID && Def->isConstant()) {
     const Type *Ty = ((const ConstPoolType*)Def)->getValue();
     unsigned ValueOffset = FirstDerivedTyID;
 
@@ -123,7 +120,7 @@
 
 bool BytecodeParser::postResolveValues(ValueTable &ValTab) {
   bool Error = false;
-  for (unsigned ty = 0; ty < ValTab.size(); ty++) {
+  for (unsigned ty = 0; ty < ValTab.size(); ++ty) {
     ValueList &DL = ValTab[ty];
     unsigned Size;
     while ((Size = DL.size())) {
@@ -180,7 +177,7 @@
     const Type *Ty = getType(Typ);
     if (Ty == 0) return true;
 
-    for (unsigned i = 0; i < NumEntries; i++) {
+    for (unsigned i = 0; i < NumEntries; ++i) {
       // Symtab entry: [def slot #][name]
       unsigned slot;
       if (read_vbr(Buf, EndBuf, slot)) return true;
@@ -211,7 +208,7 @@
 
   const MethodType::ParamTypes &Params = MTy->getParamTypes();
   for (MethodType::ParamTypes::const_iterator It = Params.begin();
-       It != Params.end(); It++) {
+       It != Params.end(); ++It) {
     MethodArgument *MA = new MethodArgument(*It);
     if (insertValue(MA, Values)) { delete M; return true; }
     M->getArgumentList().push_back(MA);
@@ -267,7 +264,7 @@
 
   Value *MethPHolder = getValue(MTy, MethSlot, false);
   assert(MethPHolder && "Something is broken no placeholder found!");
-  assert(MethPHolder->getValueType() == Value::MethodVal && "Not a method?");
+  assert(MethPHolder->isMethod() && "Not a method?");
 
   unsigned type;  // Type slot
   assert(!getTypeSlot(MTy, type) && "How can meth type not exist?");
diff --git a/lib/Bytecode/Writer/SlotCalculator.cpp b/lib/Bytecode/Writer/SlotCalculator.cpp
index 01fae37..f7eada1 100644
--- a/lib/Bytecode/Writer/SlotCalculator.cpp
+++ b/lib/Bytecode/Writer/SlotCalculator.cpp
@@ -176,12 +176,11 @@
   // Insert node into table and NodeMap...
   NodeMap[D] = Table[Ty].size();
 
-  if (Typ == Type::TypeTy &&      // If it's a type constant, add the Type also
-      D->getValueType() != Value::TypeVal) {
-    assert(D->getValueType() == Value::ConstantVal && 
-           "All Type instances should be constant types!");
-
-    const ConstPoolType *CPT = (const ConstPoolType*)D;
+  if (Typ == Type::TypeTy && !D->isType()) {
+    // If it's a type constant, add the Type also
+      
+    // All Type instances should be constant types!
+    const ConstPoolType *CPT = (const ConstPoolType*)D->castConstantAsserting();
     int Slot = getValSlot(CPT->getValue());
     if (Slot == -1) {
       // Only add if it's not already here!
diff --git a/lib/Bytecode/Writer/Writer.cpp b/lib/Bytecode/Writer/Writer.cpp
index d03c945..2be490d 100644
--- a/lib/Bytecode/Writer/Writer.cpp
+++ b/lib/Bytecode/Writer/Writer.cpp
@@ -67,7 +67,7 @@
     
     unsigned NumConstants = 0;
     for (unsigned vn = ValNo; vn < Plane.size(); vn++)
-      if (Plane[vn]->getValueType() == Value::ConstantVal)
+      if (Plane[vn]->isConstant())
 	NumConstants++;
 
     if (NumConstants == 0) continue;  // Skip empty type planes...
@@ -85,21 +85,19 @@
 
     for (; ValNo < Plane.size(); ValNo++) {
       const Value *V = Plane[ValNo];
-      if (V->getValueType() == Value::ConstantVal) {
+      if (const ConstPoolVal *CPV = V->castConstant()) {
 	//cerr << "Serializing value: <" << V->getType() << ">: " 
 	//     << ((const ConstPoolVal*)V)->getStrValue() << ":" 
 	//     << Out.size() << "\n";
-	outputConstant((const ConstPoolVal*)V);
+	outputConstant(CPV);
       }
     }
   }
 
   delete CPool;  // End bytecode block section!
 
-  if (!isMethod) { // The ModuleInfoBlock follows directly after the c-pool
-    assert(CP.getParent()->getValueType() == Value::ModuleVal);
-    outputModuleInfoBlock((const Module*)CP.getParent());
-  }
+  if (!isMethod) // The ModuleInfoBlock follows directly after the c-pool
+    outputModuleInfoBlock(CP.getParent()->castModuleAsserting());
 
   return false;
 }
@@ -108,13 +106,11 @@
   BytecodeBlock ModuleInfoBlock(BytecodeFormat::ModuleGlobalInfo, Out);
   
   // Output the types of the methods in this class
-  Module::MethodListType::const_iterator I = M->getMethodList().begin();
-  while (I != M->getMethodList().end()) {
+  for (Module::const_iterator I = M->begin(), End = M->end(); I != End; ++I) {
     int Slot = Table.getValSlot((*I)->getType());
     assert(Slot != -1 && "Module const pool is broken!");
     assert(Slot >= Type::FirstDerivedTyID && "Derived type not in range!");
     output_vbr((unsigned)Slot, Out);
-    I++;
   }
   output_vbr((unsigned)Table.getValSlot(Type::VoidTy), Out);
   align32(Out);
@@ -144,7 +140,7 @@
 void BytecodeWriter::outputSymbolTable(const SymbolTable &MST) {
   BytecodeBlock MethodBlock(BytecodeFormat::SymbolTable, Out);
 
-  for (SymbolTable::const_iterator TI = MST.begin(); TI != MST.end(); TI++) {
+  for (SymbolTable::const_iterator TI = MST.begin(); TI != MST.end(); ++TI) {
     SymbolTable::type_const_iterator I = MST.type_begin(TI->first);
     SymbolTable::type_const_iterator End = MST.type_end(TI->first);
     int Slot;
@@ -158,7 +154,7 @@
     assert(Slot != -1 && "Type in symtab, but not in table!");
     output_vbr((unsigned)Slot, Out);
 
-    for (; I != End; I++) {
+    for (; I != End; ++I) {
       // Symtab entry: [def slot #][name]
       Slot = Table.getValSlot(I->second);
       assert (Slot != -1 && "Value in symtab but not in method!!");