For PR1256:

Make Signedness information pervasive throughout all types and values.
There is no easy way to get around this. Because the GEP instruction can
index through an arbitrarily complex value structure, it is necessary to
keep track of signedness information throughout that structure. This change
makes Signedness a full class, capable of representing Signedness in
arbitrarily shaped types. The class is then used throughout llvm-upgrade to
track signedness and differentiate between globals, locals, and functions
based on their signedness.

For PR1243:
This patch also removes bogus warnings about renaming internal globals. It
now only emits such warnings when renaming non-internal globals because
they may affect linkage.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35234 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 708 insertions, 251 deletions

diff --git a/tools/llvm-upgrade/UpgradeInternals.h b/tools/llvm-upgrade/UpgradeInternals.h
index bbf6737828..0e00400796 100644
--- a/tools/llvm-upgrade/UpgradeInternals.h
+++ b/tools/llvm-upgrade/UpgradeInternals.h
@@ -21,6 +21,7 @@
 #include "llvm/Instructions.h"
 #include "llvm/ADT/StringExtras.h"
 #include <list>
+#include <iostream>
 
 
 // Global variables exported from the lexer.
@@ -32,12 +33,10 @@ extern int Upgradelineno;
 
 namespace llvm {
 
-
 class Module;
 Module* UpgradeAssembly(const std::string &infile, std::istream& in, 
                         bool debug, bool addAttrs);
 
-
 extern std::istream* LexInput;
 
 // UnEscapeLexed - Run through the specified buffer and change \xx codes to the
@@ -59,6 +58,88 @@ struct InlineAsmDescriptor {
     : AsmString(as), Constraints(c), HasSideEffects(HSE) {}
 };
 
+/// This class keeps track of the signedness of a type or value. It allows the
+/// signedness of a composite type to be captured in a relatively simple form.
+/// This is needed in order to retain the signedness of pre LLVM 2.0 types so
+/// they can be upgraded properly. Signedness of composite types must be
+/// captured in order to accurately get the signedness of a value through a
+/// GEP instruction. 
+/// @brief Class to track signedness of types and values.
+struct Signedness {
+  /// The basic kinds of signedness values.
+  enum Kind { 
+    Signless, ///< The type doesn't have any sign.
+    Unsigned, ///< The type is an unsigned integer.
+    Signed,   ///< The type is a signed integer.
+    Named,    ///< The type is a named type (probably forward ref or up ref).
+    Composite ///< The type is composite (struct, array, pointer). 
+  };
+
+private:
+  /// @brief Keeps track of Signedness for composite types
+  typedef std::vector<Signedness> SignVector;
+  Kind kind; ///< The kind of signedness node
+  union {
+    SignVector *sv;    ///< The vector of Signedness for composite types
+    std::string *name; ///< The name of the type for named types.
+  };
+public:
+  /// The Signedness class is used as a member of a union so it cannot have
+  /// a constructor or assignment operator. This function suffices.
+  /// @brief Copy one signedness value to another
+  void copy(const Signedness &that);
+  /// The Signedness class is used as a member of a union so it cannot have
+  /// a destructor.
+  /// @brief Release memory, if any allocated.
+  void destroy();
+
+  /// @brief Make a Signless node.
+  void makeSignless() { kind = Signless; sv = 0; }
+  /// @brief Make a Signed node.
+  void makeSigned()   { kind = Signed; sv = 0; }
+  /// @brief Make an Unsigned node.
+  void makeUnsigned() { kind = Unsigned; sv = 0; }
+  /// @brief Make a Named node.
+  void makeNamed(const std::string& nm){ 
+    kind = Named; name = new std::string(nm); 
+  }
+  /// @brief Make an empty Composite node.
+  void makeComposite() { kind = Composite; sv = new SignVector(); }
+  /// @brief Make an Composite node, with the first element given.
+  void makeComposite(const Signedness &S) { 
+    kind = Composite; 
+    sv = new SignVector(); 
+    sv->push_back(S);
+  }
+  /// @brief Add an element to a Composite node.
+  void add(const Signedness &S) {
+    assert(isComposite() && "Must be composite to use add");
+    sv->push_back(S);
+  }
+  bool operator<(const Signedness &that) const;
+  bool operator==(const Signedness &that) const;
+  bool isSigned() const { return kind == Signed; }
+  bool isUnsigned() const { return kind == Unsigned; }
+  bool isSignless() const { return kind == Signless; }
+  bool isNamed() const { return kind == Named; }
+  bool isComposite() const { return kind == Composite; }
+  /// This is used by GetElementPtr to extract the sign of an element.
+  /// @brief Get a specific element from a Composite node.
+  Signedness get(uint64_t idx) const {
+    assert(isComposite() && "Invalid Signedness type for get()");
+    assert(sv && idx < sv->size() && "Invalid index");
+    return (*sv)[idx];
+  }
+  /// @brief Get the name from a Named node.
+  const std::string& getName() const {
+    assert(isNamed() && "Can't get name from non-name Sign");
+    return *name;
+  }
+#ifndef NDEBUG
+  void dump() const;
+#endif
+};
+
 
 // ValID - Represents a reference of a definition of some sort.  This may either
 // be a numeric reference or a symbolic (%var) reference.  This is just a
@@ -82,41 +163,58 @@ struct ValID {
     Constant *ConstantValue; // Fully resolved constant for ConstantVal case.
     InlineAsmDescriptor *IAD;
   };
+  Signedness S;
 
   static ValID create(int Num) {
-    ValID D; D.Type = NumberVal; D.Num = Num; return D;
+    ValID D; D.Type = NumberVal; D.Num = Num; D.S.makeSignless();
+    return D;
   }
 
   static ValID create(char *Name) {
-    ValID D; D.Type = NameVal; D.Name = Name; return D;
+    ValID D; D.Type = NameVal; D.Name = Name; D.S.makeSignless();
+    return D;
   }
 
   static ValID create(int64_t Val) {
-    ValID D; D.Type = ConstSIntVal; D.ConstPool64 = Val; return D;
+    ValID D; D.Type = ConstSIntVal; D.ConstPool64 = Val; 
+    D.S.makeSigned();
+    return D;
   }
 
   static ValID create(uint64_t Val) {
-    ValID D; D.Type = ConstUIntVal; D.UConstPool64 = Val; return D;
+    ValID D; D.Type = ConstUIntVal; D.UConstPool64 = Val; 
+    D.S.makeUnsigned();
+    return D;
   }
 
   static ValID create(double Val) {
-    ValID D; D.Type = ConstFPVal; D.ConstPoolFP = Val; return D;
+    ValID D; D.Type = ConstFPVal; D.ConstPoolFP = Val;
+    D.S.makeSignless();
+    return D;
   }
 
   static ValID createNull() {
-    ValID D; D.Type = ConstNullVal; return D;
+    ValID D; D.Type = ConstNullVal;
+    D.S.makeSignless();
+    return D;
   }
 
   static ValID createUndef() {
-    ValID D; D.Type = ConstUndefVal; return D;
+    ValID D; D.Type = ConstUndefVal;
+    D.S.makeSignless();
+    return D;
   }
 
   static ValID createZeroInit() {
-    ValID D; D.Type = ConstZeroVal; return D;
+    ValID D; D.Type = ConstZeroVal;
+    D.S.makeSignless();
+    return D;
   }
   
   static ValID create(Constant *Val) {
-    ValID D; D.Type = ConstantVal; D.ConstantValue = Val; return D;
+    ValID D; D.Type = ConstantVal; D.ConstantValue = Val;
+    D.S.makeSignless();
+    return D;
   }
   
   static ValID createInlineAsm(const std::string &AsmString,
@@ -125,6 +223,7 @@ struct ValID {
     ValID D;
     D.Type = InlineAsmVal;
     D.IAD = new InlineAsmDescriptor(AsmString, Constraints, HasSideEffects);
+    D.S.makeSignless();
     return D;
   }
 
@@ -221,10 +320,6 @@ namespace OldCallingConv {
   };
 }
 
-/// An enumeration for defining the Signedness of a type or value. Signless
-/// means the signedness is not relevant to the type or value.
-enum Signedness { Signless, Unsigned, Signed };
-
 /// These structures are used as the semantic values returned from various
 /// productions in the grammar. They simply bundle an LLVM IR object with
 /// its Signedness value. These help track signedness through the various
@@ -232,31 +327,67 @@ enum Signedness { Signless, Unsigned, Signed };
 struct TypeInfo {
   const llvm::Type *T;
   Signedness S;
+  bool operator<(const TypeInfo& that) const {
+    if (this == &that)
+      return false;
+    if (T < that.T)
+      return true;
+    if (T == that.T) {
+      bool result = S < that.S;
+//#define TYPEINFO_DEBUG
+#ifdef TYPEINFO_DEBUG
+      std::cerr << (result?"true  ":"false ") << T->getDescription() << " (";
+      S.dump();
+      std::cerr << ") < " << that.T->getDescription() << " (";
+      that.S.dump();
+      std::cerr << ")\n";
+#endif
+      return result;
+    }
+    return false;
+  }
+  bool operator==(const TypeInfo& that) const {
+    if (this == &that)
+      return true;
+    return T == that.T && S == that.S;
+  }
+  void destroy() { S.destroy(); }
 };
 
 struct PATypeInfo {
   llvm::PATypeHolder* PAT;
   Signedness S;
+  void destroy() { S.destroy(); delete PAT; }
 };
 
 struct ConstInfo {
   llvm::Constant* C;
   Signedness S;
+  void destroy() { S.destroy(); }
 };
 
 struct ValueInfo {
   llvm::Value* V;
   Signedness S;
+  void destroy() { S.destroy(); }
 };
 
 struct InstrInfo {
   llvm::Instruction *I;
   Signedness S;
+  void destroy() { S.destroy(); }
+};
+
+struct TermInstInfo {
+  llvm::TerminatorInst *TI;
+  Signedness S;
+  void destroy() { S.destroy(); }
 };
 
 struct PHIListInfo {
   std::list<std::pair<llvm::Value*, llvm::BasicBlock*> > *P;
   Signedness S;
+  void destroy() { S.destroy(); delete P; }
 };
 
 } // End llvm namespace
diff --git a/tools/llvm-upgrade/UpgradeLexer.l b/tools/llvm-upgrade/UpgradeLexer.l
index ebab6db9c0..300cf5cc1a 100644
--- a/tools/llvm-upgrade/UpgradeLexer.l
+++ b/tools/llvm-upgrade/UpgradeLexer.l
@@ -51,7 +51,12 @@
 
 #define RET_TY(sym,NewTY,sign) \
   Upgradelval.PrimType.T = NewTY; \
-  Upgradelval.PrimType.S = sign; \
+  switch (sign) { \
+    case 0: Upgradelval.PrimType.S.makeSignless(); break; \
+    case 1: Upgradelval.PrimType.S.makeUnsigned(); break; \
+    case 2: Upgradelval.PrimType.S.makeSigned(); break; \
+    default: assert(0 && "Invalid sign kind"); break; \
+  }\
   return sym
 
 namespace llvm {
@@ -238,24 +243,24 @@ coldcc          { return COLDCC_TOK; }
 x86_stdcallcc   { return X86_STDCALLCC_TOK; }
 x86_fastcallcc  { return X86_FASTCALLCC_TOK; }
 
-sbyte           { RET_TY(SBYTE,  Type::Int8Ty,  Signed);  }
-ubyte           { RET_TY(UBYTE,  Type::Int8Ty,  Unsigned); }
-i8              { RET_TY(UBYTE,  Type::Int8Ty,  Unsigned); }
-short           { RET_TY(SHORT,  Type::Int16Ty, Signed);  }
-ushort          { RET_TY(USHORT, Type::Int16Ty, Unsigned); }
-i16             { RET_TY(USHORT, Type::Int16Ty, Unsigned); }
-int             { RET_TY(INT,    Type::Int32Ty, Signed);  }
-uint            { RET_TY(UINT,   Type::Int32Ty, Unsigned); }
-i32             { RET_TY(UINT,   Type::Int32Ty, Unsigned); }
-long            { RET_TY(LONG,   Type::Int64Ty, Signed);  }
-ulong           { RET_TY(ULONG,  Type::Int64Ty, Unsigned); }
-i64             { RET_TY(ULONG,  Type::Int64Ty, Unsigned); }
-void            { RET_TY(VOID,   Type::VoidTy,  Signless  ); }
-bool            { RET_TY(BOOL,   Type::Int1Ty,  Unsigned  ); }
-i1              { RET_TY(BOOL,   Type::Int1Ty,  Unsigned  ); }
-float           { RET_TY(FLOAT,  Type::FloatTy, Signless ); }
-double          { RET_TY(DOUBLE, Type::DoubleTy,Signless); }
-label           { RET_TY(LABEL,  Type::LabelTy, Signless ); }
+sbyte           { RET_TY(SBYTE,  Type::Int8Ty,  2); }
+ubyte           { RET_TY(UBYTE,  Type::Int8Ty,  1); }
+i8              { RET_TY(UBYTE,  Type::Int8Ty,  1); }
+short           { RET_TY(SHORT,  Type::Int16Ty, 2); }
+ushort          { RET_TY(USHORT, Type::Int16Ty, 1); }
+i16             { RET_TY(USHORT, Type::Int16Ty, 1); }
+int             { RET_TY(INT,    Type::Int32Ty, 2); }
+uint            { RET_TY(UINT,   Type::Int32Ty, 1); }
+i32             { RET_TY(UINT,   Type::Int32Ty, 1); }
+long            { RET_TY(LONG,   Type::Int64Ty, 2); }
+ulong           { RET_TY(ULONG,  Type::Int64Ty, 1); }
+i64             { RET_TY(ULONG,  Type::Int64Ty, 1); }
+void            { RET_TY(VOID,   Type::VoidTy,  0); }
+bool            { RET_TY(BOOL,   Type::Int1Ty,  1); }
+i1              { RET_TY(BOOL,   Type::Int1Ty,  1); }
+float           { RET_TY(FLOAT,  Type::FloatTy, 0); }
+double          { RET_TY(DOUBLE, Type::DoubleTy,0); }
+label           { RET_TY(LABEL,  Type::LabelTy, 0); }
 type            { return TYPE;   }
 opaque          { return OPAQUE; }
 
diff --git a/tools/llvm-upgrade/UpgradeParser.y b/tools/llvm-upgrade/UpgradeParser.y
index 75d85e3369..9dabc23d75 100644
--- a/tools/llvm-upgrade/UpgradeParser.y
+++ b/tools/llvm-upgrade/UpgradeParser.y
@@ -67,7 +67,7 @@ static GlobalVariable *CurGV;
 //
 typedef std::vector<Value *> ValueList;           // Numbered defs
 
-typedef std::pair<std::string,const Type*> RenameMapKey;
+typedef std::pair<std::string,TypeInfo> RenameMapKey;
 typedef std::map<RenameMapKey,std::string> RenameMapType;
 
 static void 
@@ -78,7 +78,10 @@ static struct PerModuleInfo {
   Module *CurrentModule;
   std::map<const Type *, ValueList> Values; // Module level numbered definitions
   std::map<const Type *,ValueList> LateResolveValues;
-  std::vector<PATypeHolder>    Types;
+  std::vector<PATypeHolder> Types;
+  std::vector<Signedness> TypeSigns;
+  std::map<std::string,Signedness> NamedTypeSigns;
+  std::map<std::string,Signedness> NamedValueSigns;
   std::map<ValID, PATypeHolder> LateResolveTypes;
   static Module::Endianness Endian;
   static Module::PointerSize PointerSize;
@@ -135,6 +138,9 @@ static struct PerModuleInfo {
 
     Values.clear();         // Clear out function local definitions
     Types.clear();
+    TypeSigns.clear();
+    NamedTypeSigns.clear();
+    NamedValueSigns.clear();
     CurrentModule = 0;
   }
 
@@ -208,6 +214,24 @@ static struct PerFunctionInfo {
 
 static bool inFunctionScope() { return CurFun.CurrentFunction != 0; }
 
+/// This function is just a utility to make a Key value for the rename map.
+/// The Key is a combination of the name, type, Signedness of the original 
+/// value (global/function). This just constructs the key and ensures that
+/// named Signedness values are resolved to the actual Signedness.
+/// @brief Make a key for the RenameMaps
+static RenameMapKey makeRenameMapKey(const std::string &Name, const Type* Ty, 
+                                     const Signedness &Sign) {
+  TypeInfo TI; 
+  TI.T = Ty; 
+  if (Sign.isNamed())
+    // Don't allow Named Signedness nodes because they won't match. The actual
+    // Signedness must be looked up in the NamedTypeSigns map.
+    TI.S.copy(CurModule.NamedTypeSigns[Sign.getName()]);
+  else
+    TI.S.copy(Sign);
+  return std::make_pair(Name, TI);
+}
+
 
 //===----------------------------------------------------------------------===//
 //               Code to handle definitions of all the types
@@ -233,7 +257,6 @@ static const Type *getType(const ValID &D, bool DoNotImprovise = false) {
     break;
   case ValID::NameVal:                 // Is it a named definition?
     if (const Type *N = CurModule.CurrentModule->getTypeByName(D.Name)) {
-      D.destroy();  // Free old strdup'd memory...
       return N;
     }
     break;
@@ -248,7 +271,6 @@ static const Type *getType(const ValID &D, bool DoNotImprovise = false) {
   //
   if (DoNotImprovise) return 0;  // Do we just want a null to be returned?
 
-
   if (inFunctionScope()) {
     if (D.Type == ValID::NameVal) {
       error("Reference to an undefined type: '" + D.getName() + "'");
@@ -266,13 +288,94 @@ static const Type *getType(const ValID &D, bool DoNotImprovise = false) {
   Type *Typ = OpaqueType::get();
   CurModule.LateResolveTypes.insert(std::make_pair(D, Typ));
   return Typ;
- }
+}
+
+/// This is like the getType method except that instead of looking up the type
+/// for a given ID, it looks up that type's sign.
+/// @brief Get the signedness of a referenced type
+static Signedness getTypeSign(const ValID &D) {
+  switch (D.Type) {
+  case ValID::NumberVal:               // Is it a numbered definition?
+    // Module constants occupy the lowest numbered slots...
+    if ((unsigned)D.Num < CurModule.TypeSigns.size()) {
+      return CurModule.TypeSigns[(unsigned)D.Num];
+    }
+    break;
+  case ValID::NameVal: {               // Is it a named definition?
+    std::map<std::string,Signedness>::const_iterator I = 
+      CurModule.NamedTypeSigns.find(D.Name);
+    if (I != CurModule.NamedTypeSigns.end())
+      return I->second;
+    // Perhaps its a named forward .. just cache the name
+    Signedness S;
+    S.makeNamed(D.Name);
+    return S;
+  }
+  default: 
+    break;
+  }
+  // If we don't find it, its signless
+  Signedness S;
+  S.makeSignless();
+  return S;
+}
+
+/// This function is analagous to getElementType in LLVM. It provides the same
+/// function except that it looks up the Signedness instead of the type. This is
+/// used when processing GEP instructions that need to extract the type of an
+/// indexed struct/array/ptr member. 
+/// @brief Look up an element's sign.
+static Signedness getElementSign(const ValueInfo& VI, 
+                                 const std::vector<Value*> &Indices) {
+  const Type *Ptr = VI.V->getType();
+  assert(isa<PointerType>(Ptr) && "Need pointer type");
+
+  unsigned CurIdx = 0;
+  Signedness S(VI.S);
+  while (const CompositeType *CT = dyn_cast<CompositeType>(Ptr)) {
+    if (CurIdx == Indices.size())
+      break;
+
+    Value *Index = Indices[CurIdx++];
+    assert(!isa<PointerType>(CT) || CurIdx == 1 && "Invalid type");
+    Ptr = CT->getTypeAtIndex(Index);
+    if (const Type* Ty = Ptr->getForwardedType())
+      Ptr = Ty;
+    assert(S.isComposite() && "Bad Signedness type");
+    if (isa<StructType>(CT)) {
+      S = S.get(cast<ConstantInt>(Index)->getZExtValue());
+    } else {
+      S = S.get(0UL);
+    }
+    if (S.isNamed())
+      S = CurModule.NamedTypeSigns[S.getName()];
+  }
+  Signedness Result;
+  Result.makeComposite(S);
+  return Result;
+}
+
+/// This function just translates a ConstantInfo into a ValueInfo and calls
+/// getElementSign(ValueInfo,...). Its just a convenience.
+/// @brief ConstantInfo version of getElementSign.
+static Signedness getElementSign(const ConstInfo& CI, 
+                                 const std::vector<Constant*> &Indices) {
+  ValueInfo VI;
+  VI.V = CI.C;
+  VI.S.copy(CI.S);
+  std::vector<Value*> Idx;
+  for (unsigned i = 0; i < Indices.size(); ++i)
+    Idx.push_back(Indices[i]);
+  Signedness result = getElementSign(VI, Idx);
+  VI.destroy();
+  return result;
+}
 
 /// This function determines if two function types differ only in their use of
 /// the sret parameter attribute in the first argument. If they are identical 
 /// in all other respects, it returns true. Otherwise, it returns false.
-bool FuncTysDifferOnlyBySRet(const FunctionType *F1, 
-                                   const FunctionType *F2) {
+static bool FuncTysDifferOnlyBySRet(const FunctionType *F1, 
+                                    const FunctionType *F2) {
   if (F1->getReturnType() != F2->getReturnType() ||
       F1->getNumParams() != F2->getNumParams() ||
       F1->getParamAttrs(0) != F2->getParamAttrs(0))
@@ -287,10 +390,27 @@ bool FuncTysDifferOnlyBySRet(const FunctionType *F1,
   return true;
 }
 
+/// This function determines if the type of V and Ty differ only by the SRet
+/// parameter attribute. This is a more generalized case of
+/// FuncTysDIfferOnlyBySRet since it doesn't require FunctionType arguments.
+static bool TypesDifferOnlyBySRet(Value *V, const Type* Ty) {
+  if (V->getType() == Ty)
+    return true;
+  const PointerType *PF1 = dyn_cast<PointerType>(Ty);
+  const PointerType *PF2 = dyn_cast<PointerType>(V->getType());
+  if (PF1 && PF2) {
+    const FunctionType* FT1 = dyn_cast<FunctionType>(PF1->getElementType());
+    const FunctionType* FT2 = dyn_cast<FunctionType>(PF2->getElementType());
+    if (FT1 && FT2)
+      return FuncTysDifferOnlyBySRet(FT1, FT2);
+  }
+  return false;
+}
+
 // The upgrade of csretcc to sret param attribute may have caused a function 
 // to not be found because the param attribute changed the type of the called 
 // function. This helper function, used in getExistingValue, detects that
-// situation and returns V if it occurs and 0 otherwise. 
+// situation and bitcasts the function to the correct type.
 static Value* handleSRetFuncTypeMerge(Value *V, const Type* Ty) {
   // Handle degenerate cases
   if (!V)
@@ -298,23 +418,21 @@ static Value* handleSRetFuncTypeMerge(Value *V, const Type* Ty) {
   if (V->getType() == Ty)
     return V;
 
-  Value* Result = 0;
   const PointerType *PF1 = dyn_cast<PointerType>(Ty);
   const PointerType *PF2 = dyn_cast<PointerType>(V->getType());
   if (PF1 && PF2) {
-    const FunctionType *FT1 =
-      dyn_cast<FunctionType>(PF1->getElementType());
-    const FunctionType *FT2 =
-      dyn_cast<FunctionType>(PF2->getElementType());
+    const FunctionType *FT1 = dyn_cast<FunctionType>(PF1->getElementType());
+    const FunctionType *FT2 = dyn_cast<FunctionType>(PF2->getElementType());
     if (FT1 && FT2 && FuncTysDifferOnlyBySRet(FT1, FT2))
       if (FT2->paramHasAttr(1, FunctionType::StructRetAttribute))
-        Result = V;
+        return V;
       else if (Constant *C = dyn_cast<Constant>(V))
-        Result = ConstantExpr::getBitCast(C, PF1);
+        return ConstantExpr::getBitCast(C, PF1);
       else
-        Result = new BitCastInst(V, PF1, "upgrd.cast", CurBB);
+        return new BitCastInst(V, PF1, "upgrd.cast", CurBB);
+      
   }
-  return Result;
+  return 0;
 }
 
 // getExistingValue - Look up the value specified by the provided type and
@@ -350,9 +468,8 @@ static Value *getExistingValue(const Type *Ty, const ValID &D) {
 
   case ValID::NameVal: {                // Is it a named definition?
     // Get the name out of the ID
-    std::string Name(D.Name);
-    Value* V = 0;
-    RenameMapKey Key = std::make_pair(Name, Ty);
+    RenameMapKey Key = makeRenameMapKey(D.Name, Ty, D.S);
+    Value *V = 0;
     if (inFunctionScope()) {
       // See if the name was renamed
       RenameMapType::const_iterator I = CurFun.RenameMap.find(Key);
@@ -360,10 +477,12 @@ static Value *getExistingValue(const Type *Ty, const ValID &D) {
       if (I != CurFun.RenameMap.end())
         LookupName = I->second;
       else
-        LookupName = Name;
+        LookupName = D.Name;
       ValueSymbolTable &SymTab = CurFun.CurrentFunction->getValueSymbolTable();
       V = SymTab.lookup(LookupName);
-      V = handleSRetFuncTypeMerge(V, Ty);
+      if (V && V->getType() != Ty)
+        V = handleSRetFuncTypeMerge(V, Ty);
+      assert((!V || TypesDifferOnlyBySRet(V, Ty)) && "Found wrong type");
     }
     if (!V) {
       RenameMapType::const_iterator I = CurModule.RenameMap.find(Key);
@@ -371,9 +490,11 @@ static Value *getExistingValue(const Type *Ty, const ValID &D) {
       if (I != CurModule.RenameMap.end())
         LookupName = I->second;
       else
-        LookupName = Name;
+        LookupName = D.Name;
       V = CurModule.CurrentModule->getValueSymbolTable().lookup(LookupName);
-      V = handleSRetFuncTypeMerge(V, Ty);
+      if (V && V->getType() != Ty)
+        V = handleSRetFuncTypeMerge(V, Ty);
+      assert((!V || TypesDifferOnlyBySRet(V, Ty)) && "Found wrong type");
     }
     if (!V) 
       return 0;
@@ -506,14 +627,13 @@ static BasicBlock *getBBVal(const ValID &ID, bool isDefinition = false) {
     break;
   case ValID::NameVal:                  // Is it a named definition?
     Name = ID.Name;
-    if (Value *N = CurFun.CurrentFunction->
-                   getValueSymbolTable().lookup(Name)) {
+    if (Value *N = CurFun.CurrentFunction->getValueSymbolTable().lookup(Name)) {
       if (N->getType() != Type::LabelTy) {
         // Register names didn't use to conflict with basic block names
         // because of type planes. Now they all have to be unique. So, we just
         // rename the register and treat this name as if no basic block
         // had been found.
-        RenameMapKey Key = std::make_pair(N->getName(),N->getType());
+        RenameMapKey Key = makeRenameMapKey(ID.Name, N->getType(), ID.S);
         N->setName(makeNameUnique(N->getName()));
         CurModule.RenameMap[Key] = N->getName();
         BB = 0;
@@ -624,19 +744,33 @@ ResolveDefinitions(std::map<const Type*,ValueList> &LateResolvers,
   LateResolvers.clear();
 }
 
-// ResolveTypeTo - A brand new type was just declared.  This means that (if
-// name is not null) things referencing Name can be resolved.  Otherwise, things
-// refering to the number can be resolved.  Do this now.
-//
-static void ResolveTypeTo(char *Name, const Type *ToTy) {
+/// This function is used for type resolution and upref handling. When a type
+/// becomes concrete, this function is called to adjust the signedness for the
+/// concrete type.
+static void ResolveTypeSign(const Type* oldTy, const Signedness &Sign) {
+  std::string TyName = CurModule.CurrentModule->getTypeName(oldTy);
+  if (!TyName.empty())
+    CurModule.NamedTypeSigns[TyName] = Sign;
+}
+
+/// ResolveTypeTo - A brand new type was just declared.  This means that (if
+/// name is not null) things referencing Name can be resolved.  Otherwise, 
+/// things refering to the number can be resolved.  Do this now.
+static void ResolveTypeTo(char *Name, const Type *ToTy, const Signedness& Sign){
   ValID D;
-  if (Name) D = ValID::create(Name);
-  else      D = ValID::create((int)CurModule.Types.size());
+  if (Name)
+    D = ValID::create(Name);
+  else      
+    D = ValID::create((int)CurModule.Types.size());
+  D.S.copy(Sign);
+
+  CurModule.NamedTypeSigns[Name] = Sign;
 
   std::map<ValID, PATypeHolder>::iterator I =
     CurModule.LateResolveTypes.find(D);
   if (I != CurModule.LateResolveTypes.end()) {
-    ((DerivedType*)I->second.get())->refineAbstractTypeTo(ToTy);
+    const Type *OldTy = I->second.get();
+    ((DerivedType*)OldTy)->refineAbstractTypeTo(ToTy);
     CurModule.LateResolveTypes.erase(I);
   }
 }
@@ -696,12 +830,12 @@ static inline bool TypeHasInteger(const Type *Ty) {
 // null potentially, in which case this is a noop.  The string passed in is
 // assumed to be a malloc'd string buffer, and is free'd by this function.
 //
-static void setValueName(Value *V, char *NameStr) {
+static void setValueName(const ValueInfo &V, char *NameStr) {
   if (NameStr) {
     std::string Name(NameStr);      // Copy string
     free(NameStr);                  // Free old string
 
-    if (V->getType() == Type::VoidTy) {
+    if (V.V->getType() == Type::VoidTy) {
       error("Can't assign name '" + Name + "' to value with void type");
       return;
     }
@@ -714,13 +848,13 @@ static void setValueName(Value *V, char *NameStr) {
     if (Existing) {
       // An existing value of the same name was found. This might have happened
       // because of the integer type planes collapsing in LLVM 2.0. 
-      if (Existing->getType() == V->getType() &&
+      if (Existing->getType() == V.V->getType() &&
           !TypeHasInteger(Existing->getType())) {
         // If the type does not contain any integers in them then this can't be
         // a type plane collapsing issue. It truly is a redefinition and we 
         // should error out as the assembly is invalid.
         error("Redefinition of value named '" + Name + "' of type '" +
-              V->getType()->getDescription() + "'");
+              V.V->getType()->getDescription() + "'");
         return;
       } 
       // In LLVM 2.0 we don't allow names to be re-used for any values in a 
@@ -734,13 +868,13 @@ static void setValueName(Value *V, char *NameStr) {
       // We're changing the name but it will probably be used by other 
       // instructions as operands later on. Consequently we have to retain
       // a mapping of the renaming that we're doing.
-      RenameMapKey Key = std::make_pair(Name,V->getType());
+      RenameMapKey Key = makeRenameMapKey(Name, V.V->getType(), V.S);
       CurFun.RenameMap[Key] = NewName;
       Name = NewName;
     }
 
     // Set the name.
-    V->setName(Name);
+    V.V->setName(Name);
   }
 }
 
@@ -749,7 +883,8 @@ static void setValueName(Value *V, char *NameStr) {
 static GlobalVariable *
 ParseGlobalVariable(char *NameStr,GlobalValue::LinkageTypes Linkage,
                     bool isConstantGlobal, const Type *Ty,
-                    Constant *Initializer) {
+                    Constant *Initializer,
+                    const Signedness &Sign) {
   if (isa<FunctionType>(Ty))
     error("Cannot declare global vars of function type");
 
@@ -769,6 +904,7 @@ ParseGlobalVariable(char *NameStr,GlobalValue::LinkageTypes Linkage,
   } else {
     ID = ValID::create((int)CurModule.Values[PTy].size());
   }
+  ID.S.makeComposite(Sign);
 
   if (GlobalValue *FWGV = CurModule.GetForwardRefForGlobal(PTy, ID)) {
     // Move the global to the end of the list, from whereever it was
@@ -794,13 +930,7 @@ ParseGlobalVariable(char *NameStr,GlobalValue::LinkageTypes Linkage,
       // There is alread a global of the same name which means there is a
       // conflict. Let's see what we can do about it.
       std::string NewName(makeNameUnique(Name));
-      if (Linkage == GlobalValue::InternalLinkage) {
-        // The linkage type is internal so just warn about the rename without
-        // invoking "scarey language" about linkage failures. GVars with
-        // InternalLinkage can be renamed at will.
-        warning("Global variable '" + Name + "' was renamed to '"+ 
-                NewName + "'");
-      } else {
+      if (Linkage != GlobalValue::InternalLinkage) {
         // The linkage of this gval is external so we can't reliably rename 
         // it because it could potentially create a linking problem.  
         // However, we can't leave the name conflict in the output either or 
@@ -811,7 +941,7 @@ ParseGlobalVariable(char *NameStr,GlobalValue::LinkageTypes Linkage,
       }
 
       // Put the renaming in the global rename map
-      RenameMapKey Key = std::make_pair(Name,PointerType::get(Ty));
+      RenameMapKey Key = makeRenameMapKey(Name, PointerType::get(Ty), ID.S);
       CurModule.RenameMap[Key] = NewName;
 
       // Rename it
@@ -824,6 +954,8 @@ ParseGlobalVariable(char *NameStr,GlobalValue::LinkageTypes Linkage,
     new GlobalVariable(Ty, isConstantGlobal, Linkage, Initializer, Name,
                        CurModule.CurrentModule);
   InsertValue(GV, CurModule.Values);
+  // Remember the sign of this global.
+  CurModule.NamedValueSigns[Name] = ID.S;
   return GV;
 }
 
@@ -834,21 +966,26 @@ ParseGlobalVariable(char *NameStr,GlobalValue::LinkageTypes Linkage,
 // This function returns true if the type has already been defined, but is
 // allowed to be redefined in the specified context.  If the name is a new name
 // for the type plane, it is inserted and false is returned.
-static bool setTypeName(const Type *T, char *NameStr) {
+static bool setTypeName(const PATypeInfo& TI, char *NameStr) {
   assert(!inFunctionScope() && "Can't give types function-local names");
   if (NameStr == 0) return false;
  
   std::string Name(NameStr);      // Copy string
   free(NameStr);                  // Free old string
 
+  const Type* Ty = TI.PAT->get();
+
   // We don't allow assigning names to void type
-  if (T == Type::VoidTy) {
+  if (Ty == Type::VoidTy) {
     error("Can't assign name '" + Name + "' to the void type");
     return false;
   }
 
   // Set the type name, checking for conflicts as we do so.
-  bool AlreadyExists = CurModule.CurrentModule->addTypeName(Name, T);
+  bool AlreadyExists = CurModule.CurrentModule->addTypeName(Name, Ty);
+
+  // Save the sign information for later use 
+  CurModule.NamedTypeSigns[Name] = TI.S;
 
   if (AlreadyExists) {   // Inserting a name that is already defined???
     const Type *Existing = CurModule.CurrentModule->getTypeByName(Name);
@@ -858,7 +995,7 @@ static bool setTypeName(const Type *T, char *NameStr) {
     // opaque type.  In this case, Existing will be an opaque type.
     if (const OpaqueType *OpTy = dyn_cast<OpaqueType>(Existing)) {
       // We ARE replacing an opaque type!
-      const_cast<OpaqueType*>(OpTy)->refineAbstractTypeTo(T);
+      const_cast<OpaqueType*>(OpTy)->refineAbstractTypeTo(Ty);
       return true;
     }
 
@@ -866,11 +1003,11 @@ static bool setTypeName(const Type *T, char *NameStr) {
     // the redefinition is identical to the original. This will be so if
     // Existing and T point to the same Type object. In this one case we
     // allow the equivalent redefinition.
-    if (Existing == T) return true;  // Yes, it's equal.
+    if (Existing == Ty) return true;  // Yes, it's equal.
 
     // Any other kind of (non-equivalent) redefinition is an error.
     error("Redefinition of type named '" + Name + "' in the '" +
-          T->getDescription() + "' type plane");
+          Ty->getDescription() + "' type plane");
   }
 
   return false;
@@ -902,7 +1039,7 @@ namespace {
     OpaqueType *UpRefTy;
 
     UpRefRecord(unsigned NL, OpaqueType *URTy)
-      : NestingLevel(NL), LastContainedTy(URTy), UpRefTy(URTy) {}
+      : NestingLevel(NL), LastContainedTy(URTy), UpRefTy(URTy) { }
   };
 }
 
@@ -916,7 +1053,7 @@ static std::vector<UpRefRecord> UpRefs;
 /// count reaches zero, the upreferenced type is the type that is passed in:
 /// thus we can complete the cycle.
 ///
-static PATypeHolder HandleUpRefs(const Type *ty) {
+static PATypeHolder HandleUpRefs(const Type *ty, const Signedness& Sign) {
   // If Ty isn't abstract, or if there are no up-references in it, then there is
   // nothing to resolve here.
   if (!ty->isAbstract() || UpRefs.empty()) return ty;
@@ -932,10 +1069,11 @@ static PATypeHolder HandleUpRefs(const Type *ty) {
   // this variable.
   OpaqueType *TypeToResolve = 0;
 
-  for (unsigned i = 0; i != UpRefs.size(); ++i) {
+  unsigned i = 0;
+  for (; i != UpRefs.size(); ++i) {
     UR_OUT("  UR#" << i << " - TypeContains(" << Ty->getDescription() << ", "
-           << UpRefs[i].second->getDescription() << ") = "
-           << (TypeContains(Ty, UpRefs[i].second) ? "true" : "false") << "\n");
+           << UpRefs[i].UpRefTy->getDescription() << ") = "
+           << (TypeContains(Ty, UpRefs[i].UpRefTy) ? "true" : "false") << "\n");
     if (TypeContains(Ty, UpRefs[i].LastContainedTy)) {
       // Decrement level of upreference
       unsigned Level = --UpRefs[i].NestingLevel;
@@ -946,8 +1084,9 @@ static PATypeHolder HandleUpRefs(const Type *ty) {
           TypeToResolve = UpRefs[i].UpRefTy;
         } else {
           UR_OUT("  * Resolving upreference for "
-                 << UpRefs[i].second->getDescription() << "\n";
-                 std::string OldName = UpRefs[i].UpRefTy->getDescription());
+                 << UpRefs[i].UpRefTy->getDescription() << "\n";
+          std::string OldName = UpRefs[i].UpRefTy->getDescription());
+          ResolveTypeSign(UpRefs[i].UpRefTy, Sign);
           UpRefs[i].UpRefTy->refineAbstractTypeTo(TypeToResolve);
           UR_OUT("  * Type '" << OldName << "' refined upreference to: "
                  << (const void*)Ty << ", " << Ty->getDescription() << "\n");
@@ -960,14 +1099,113 @@ static PATypeHolder HandleUpRefs(const Type *ty) {
 
   if (TypeToResolve) {
     UR_OUT("  * Resolving upreference for "
-           << UpRefs[i].second->getDescription() << "\n";
+           << UpRefs[i].UpRefTy->getDescription() << "\n";
            std::string OldName = TypeToResolve->getDescription());
+    ResolveTypeSign(TypeToResolve, Sign);
     TypeToResolve->refineAbstractTypeTo(Ty);
   }
 
   return Ty;
 }
 
+bool Signedness::operator<(const Signedness &that) const {
+  if (isNamed()) {
+    if (that.isNamed()) 
+      return *(this->name) < *(that.name);
+    else
+      return CurModule.NamedTypeSigns[*name] < that;
+  } else if (that.isNamed()) {
+    return *this < CurModule.NamedTypeSigns[*that.name];
+  }
+
+  if (isComposite() && that.isComposite()) {
+    if (sv->size() == that.sv->size()) {
+      SignVector::const_iterator thisI = sv->begin(), thisE = sv->end();
+      SignVector::const_iterator thatI = that.sv->begin(), 
+                                 thatE = that.sv->end();
+      for (; thisI != thisE; ++thisI, ++thatI) {
+        if (*thisI < *thatI)
+          return true;
+        else if (!(*thisI == *thatI))
+          return false;